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Mitosis and Meiosis - NANSLO Lab Activity

Page history last edited by Sue Schmidt 9 years, 3 months ago

 

NANSLO REMOTE LAB ACTIVITY

 

SUBJECT SEMESTER: XXXXXXXXXXXXXXXXXXXXX

TYPE OF LAB:  XXXXXXXXXXXXXXXXXXXX

 

 

 

 

 

 

 

 

TITLE OF LAB:  Mitosis and Meiosis


Mitosis and Meiosis NANSLO Lab Activity in Word Format last updated April 25, 2014.

 

Lab format: This lab is a remote lab activity.

 

Relationship to theory (if appropriate): In this lab you will be examining the underlying processes that make up the cell cycle.

 

Instructions for Instructors:  This protocol is written under an open source CC BY license. You may use the procedure as is or modify as necessary for your class.  Be sure to let your students know if they should complete optional exercises in this lab procedure as lab technicians will not know if you want your students to complete optional exercise.

 

Instructions for Students:  Read the complete laboratory procedure before coming to lab.  Under the experimental sections, complete all pre-lab materials before logging on to the remote lab, complete data collection sections during your on-line period, and answer questions in analysis sections after your on-line period.  Your instructor will let you know if you are required to complete any optional exercises in this lab.

 

Remote Resources:  Primary - Microscope; Secondary - Mitosis and Meiosis Slide Set.

 

CONTENTS FOR THIS NANSLO LAB ACTIVITY:

 

Learning Objectives
Background Information
Equipment
Experimental Procedure
Exercise 1:  Mitosis in animal and plant cells
Exercise 2:  Calculate the percentage of time spent in each stage of mitosis
Exercise 3:  Growth in the onion root
Exercise 4:  Stages of meiosis
Exercise 5:  Meiosis in humans (optional)
Summary Questions:  Mitosis and meiosis experiment

Preparing to Use the Remote Web-based Science Lab (RWSL)

 

LEARNING OBJECTIVES:

 

After completing this laboratory experiment, you should be able to do the following things:

  1. Describe the cell cycle.
  2. Identify the stages of mitosis from prepared slides.
  3. Calculate the percentage of time a cell spends in each stage of the cell cycle.
  4. Quantify the relationship between cell division and cell growth.
  5. Recognize the processes of meiosis and how it differs from mitosis.
  6. Identify support cells from human spermatogenesis and oogenesis (ptional).

 

BACKGROUND INFORMATION:

 

If I asked you “Where do cells come from?” what would you answer? In modern biology our understanding of a the cell as the basic building block of life is codified in a set of principles called the Cell Theory which was first codified by Schleiden and Schwann in 1838-39.  The cell theory is second only to the theory of evolution by natural selection in understanding the relatedness of life.  Cell Theory says the following: 

 

  1. All living organisms are composed of one or more cells.
  2. Cells are the basic building blocks of all life.
  3. All cells are descended from a preexisting cell.

 

While these may seem like relative simple points it took scientists several centuries to produce the cell theory.

The development of the cell theory directly follows the development of the microscope. The name “cell” was coined by Robert Hooke6 in 1665. While observing a piece of cork under his microscope he thought that the microscopic units that made up the cork looked like the rooms, or  “cella” in Latin, that monks lived in. This was closely followed by the discovery of single celled organisms by Antoni van Leeuwenhoek3-5 in 1676. Leeuwenhoek discovered motile microscopic particles by examining scrapings from his teeth under his microscope. In 1838 Metthias Schleiden7 and Theodor Schwann8 presented evidence that all plants and animals are composed of cells. However, there were still some questions as to where cells came from, as Schleiden believed cells formed through a process of crystallization.  This theory was simply a variant on the belief of Aristotle that life could come into existence by spontaneous generation.

It was not until the 1850s that a group of scientist was able to show that new cells were produced from preexisting cells9. However, most scientists believe the definitive test disproving spontaneous creation of microbial life was conducted by Louis Pasteur in 186210. In Pasteur’s experiment two flasks were each set-up with bacterial growing broth (a liquid that is conducive to the growth of bacteria) and sterilized.  Both flasks were left open to the air but in such a way that dust could enter only flask 1 not flask 2. After a period of time bacteria growth was seen in only flask 1 and not in flask 2.  This showed that dust (bacteria) had to be added to the broth in order for bacteria to grow.

In this lab we will be examining the mechanism underlying the third principle of the cell theory “that all cells are descended from preexisting cells”.  There are two processes involving the production on new cells, the first process, mitosis, is used for growth and to replace old or dead cells.  The second process, meiosis, is used to produce gametes (egg and sperm) cells that are used for sexual reproduction. An important point to keep in mind is that we name the type of cell cycle based on what is happening to the nucleus and genetic material.    

The mitotic cell cycle (see Figure 1) is used to produce new somatic (body) cells in the organism. The mitotic cell cycle in the simplest form is composed of two parts Interstage and Mitosis.  However, each of these parts can be further divided. Mitosis can be divided into four parts: Prostage, Metastage, Anastage, and Telostage which will be described below. Mitosis, in fact, means the division of the nucleus to produce two identical daughter cells.  The division of the cell itself is called cytokinesis and overlaps telostage but is not actually classified as part of it.    Interstage (the part of the cell cycle between actual divisions) is composed of three parts Gap1 (sometimes referred to as growth1) the cell grows and performs normal cellular functions, Synthesis (s stage) DNA is replicated, and Gap2 (sometimes referred to as growth2) is where the cellular organelles are replicated. There is one additional stage to the cell cycle Gap0. A cell that has stopped cycling (dividing) either temporarily or permanently has entered Gap0.

 

The different stages of the cell cycle were identified as morphological changes by Waclaw Mayzel in 18751-2.  All these morphological changes can be observed in a compound microscope. During Interstage (figure 2A) there is a clearly defined nuclear envelope filled with dispersed chromosomes.  As the cell enters Prostage (figure 2B) the chromosomes condense and the mitotic spindle forms. At this point each chromosome is composed of two sister chromatids joined at the centromere.  Additionally, the nuclear envelope breaks down and the mitotic spindle begins attaching to the chromosomes at the centromere. (In some texts the breakdown of the nuclear envelope and the attachment of the mitotic spindle to the chromosomes is listed as an additional stage Prometaphase).  In Metaphase (figure 2C) the chromosomes line up in the middle of the cell forming a structure called the metaphase plate.  During Anaphase (figure 2D) the centromere splits and each chromatid now a chromosome is pulled to opposite sides of the cell.  In the last stage Telophase (figure 2E) the chromosomes become less condensed, two new nuclei form and the mitotic spindle de polymerizes.  This officially ends mitosis which as mentioned before is the replication and division of the nucleus.  The cell cycle ends with cytokinesis, the division of the cytoplasm, which often overlaps late telophase.

 

Figure 2: Stages of Mitosis - A) Interphace; B) Prophase; C) Metaphase; D) Analphase; and E) Telophase (Cytokinesis)

The other type of cell cycle is called meiosis and is used in sexual reproduction to produce gametes (sperm and egg in most animals and plants). In plants and animals each organism contains two copies of each chromosome; this is called diploid.  In order for sexual reproduction to occur properly the number of chromosomes need to be reduced by half; which is called haploid.  If the chromosome number was not reduced by half then each new generation would have twice the number of chromosomes as the previous organism; which is called polyploidy.  In many organisms a state of polyploidy causes biological defects.

 

 

 

 

 

Figure 3: Sperm and Egg Meiosis

Mechanistically meiosis differs from mitosis in that two rounds of cell division occur, referred to as meiosis I and meiosis II, with only one round of DNA synthesis. Figure 3 shows the stages of meiosis were there are differences between the corresponding mitotic and meiotic stages.  This produces 4 haploid cells; the number of mature gametes varies depending on whether the final mature cell is a sperm cell or egg cell (Figure 3).  In meiosis I S stage occurs as normal.  The first difference between mitosis and meiosis I occurs in Prophase I, during Prophase I the homologous chromosomes pair up and exchange genetic material by crossover (Figure 3).  This exchange of genetic material increases the genetic variation in the offspring.  The next difference occurs in anaphase I, during anaphase I instead of the centromere dividing it stays connected and the homologous chromosomes are segregated to the opposite poles (Figure 3). During Cytokinesis I we see the first difference between spermatogenesis (sperm formation) and oogenesis (egg formation).  During cytokinesis of the egg the cytoplasm divides unequally with one of the daughter cells getting most of the cytoplasm, the smaller cell is called a polar body (Figure 3B).  The presperm cells undergo an equal cytokinesis (Figure 3A).  The cells will then enter a second cell cycle, meiosis II, without replicating DNA.  The length of interphase between meiosis I and meiosis II varies from nonexistent too years depending on the organism. In meiosis II during Anaphase II the kinetochore divides and the sister chromatids are pulled to opposite poles of the cell.  Again the in oogenesis the cell undergoes unequal cytokinesis producing an oogonia and another polar body, while the sperm cells divide equally.  This produces four haploid spermatocytes in the male line and one haploid oogonia and 2 or 3 haploid polar bodies in the female line.  The spermatocytes and oogonia go on to mature in to sperm and egg cells, which will give rise to a new generation.

 

Now that we have and understanding of the mechanisms of mitosis and meiosis it is clear how each separately links to the third principle of the cell theory: all cells descend from preexisting cells.  For instance we know that new somatic cells arise from mitosis, when an older cell divides.  Additionally, we know that the development of a new multi cellular organism starts with the fusion of two gametes (fertilization) which produces a zygote. The remaining question though is how does mitosis and meiosis relate to each other.  The answer to this question depends on whether we are talking about a multi cellular animal or plant.  In multicellar animals the zygote divides a few times mitotically then the cells are separated into two populations one population will continue to divide mitotically and will go on to form all the somatic cells.  The second population will form the germline (Figure 4A).  In plants the first few stages are the same, the difference occurs in that a population of cells is not set aside to form a germline (Figure 4B).  Instead germline cells are recruited from the somatic cells when they are needed.

 

References:

  1. Medycyna, czasopismo tygodniowe dla lekarzy (1875; 3(45), 409/0412)
  2. Centralblatt f. die Med. Wissenschaften  (1875; 50: 849–852)
  3. Dobell, C. Antony van Leeuwenhoek and His “Little Animals” (Dover, New York, 1960).
  4. Wolpert, L. Curr. Biol. 6, 225–228 (1995).
  5. Singer, S. A Short History of Biology (Clarendon, Oxford, 1931).
  6. Westfall, R. S. Hooke, Robert in Dictionary of Scientific Biography Vol. 7 (ed. Gillespie, C.) 481–488 (Scribner, New York, 1980).
  7. Schleiden, M. J. Arch. Anat. Physiol. Wiss. Med. 13, 137–176 (1838).
  8. Schwann, T. Mikroskopische Untersuchungen über die Übereinstimmung in der Struktur und dem Wachstum der Tiere und Pflanzen (Sander’schen Buchhandlung, Berlin, 1839).
  9. Mayr, E. The Growth of the Biological Thought (Belknap, Cambridge, MA, 1982).
  10. Pasteur, L. A. Ann. Sci. Nat. (part. zool.) 16, 5–98 (1861).

 

EQUIPMENT:

 

  • Paper

  • Pencil/pen

  • Slides

    • Onion Root Tip

    • Whitefish Blastula

    • Mammal Graafian Follicles

    • Human Testis

    • Ascaris lumbricoides

    • Grasshopper Testis

  • Computer (access to remote laboratory

 

EXPERIMENTAL PROCEDURE:

 

Once you have logged on to the remote lab system, you will perform the following laboratory procedures.  See Preparing for the Microscope NANSLO Lab Activity below.

 

EXERCISE 1:  Mitosis in Animal and Plant Cells 

 

Figure 5: Onion Root TipPRE-LAB:

 

New cells are produced in animals and plants by the division of old cells.  These new cells can be used for growth or to replace dead or damaged cells.  As stated in the introduction, the cell cycle is divided into two parts the replication and division of the genetic material (mitosis) and the division of the cytoplasm (cytokinesis).  In this experiment you will use prepared slides of an onion root tip and a whitefish blastula to identify the stages of mitosis.

The onion root tip is divided into four sections based on the behavior and function of the cells (Figure 5).  The first region is the root cap which protects the growing root.  The second is the meristeam, a region of highly mitotically active cells. Then there are the elongation regions where cells are growing, and then lastly the maturation region where cells become fully mature root cells. While the onion root tip is divided into four cell population (root cap, meristeam, elongation and maturation) at the developmental stage of development you are looking at, the cells in the white fish blastula are a uniform population.

PRE-LAB QUESTIONS:

 

  1. Do you think you will see any differences between plant or animal cells?  What differences do you think you will see?
  2. Rewrite your answer to question one in the form of an If ... Then . . . hypotheses.


DATA COLLECTION:

  1. Select the prepared slide of the whitefish blastula (Slide Cassette 1:  #7) using the RWSL microscope controls.

  2. Locate the blastula.  Then carefully work your  way through all objectives, focusing with each one, until you reach the 40X or 60X objective and, working as a group, identify a cell in each stage of mitosis. Use the “capture image” feature on the RWSL microscope control panel to capture an image of each stage. (Each member of your group should use the microscope to identify at least one stage.)

  3. Select the prepared slide of the onion root tip (Slide Cassette 1:  #8) using the RWSL microscope controls.
  4. Locate the onion root tip.  Then carefully work your way through all the objectives, focusing with each one, until you reach the 40X or 60X objective and, working as a group, identify the stages of mitosis.  Use the “capture image” feature on the RWSL control panel to capture an image of each stage. (Each member of your group should use the microscope to identify at least one stage.)


ANALYSIS:

  1. Use the insert images from question 4 and the insert and text box features on your computer's word processing program.  Label the plasma membrane, chromosomes, mitotic spindle, nuclear membrane, and centriole for each blastula mitotic stage image as appropriate. (Place images below.)

  2. Use the images from question 6 and the insert and text box features on your computer word processing program.  Label the plasma membrane, chromosomes, mitotic spindle, nuclear membrane, and centriole for each onion root tip mitotic stage image as appropriate.  (Place your images below.)

  3. Think back to the pre-lab questions about differences in plant and animal cell mitosis.  Were you prediction correct?  What, if any, differences did you actually see?

  4. If your predictions were incorrect, revise your hypotheses based on your new understanding of the differences between mitosis in plants and animals.

 

EXERCISE 2:  Calculate the percentage of time spent in each state og mitosis.

 

PRE-LAB:

 

At the time when the whitefish blastula slide was prepared, the cells were arrested at their current stage within the cell cycle by fixation, which is a chemical reaction that stops the biological process in the cell. Fixation also preserves the tissues by immobilizes the cells, organelles, and proteins through chemical cross linking. The duration of each stage of the cell cycle in the blastula can be estimated by determining the proportion of cells arrested at each stage of mitosis with respect to the number of cells in interstage.

Let’s assume that you examined a slide and determined the stage at which 100 cells were arrested by fixation. It is known that whitefish blastula cells take about 24 hours to complete the cell cycle. By determining the percentage of cells in each stage of mitosis and in Interstage, you can calculate the amount of time spent in each stage. For example, if ten cells out of 100 were found to be in Prostage, the percentage of cells is 10/100 x 100 = 10%. This shows that any one of the hypothetical cells spends 10% of the time in Prostage, so they spend 0.10 x 24 hours or 2.4 hr (2 hr and 24 min) in that stage.

 

PRE-LAB QUESTIONS:

  1. Create a table to record your data.  Insert table below. 


DATA COLLECTION:

  1. Select the whitefish blastula slide (Slide Cassette 1:  #7).  Select an area of a blastula so that your entire field of view is filled with cells.

  2. Count and record the number of the cells in each stage of the cell cycle in your field of view.  Enter this information in the table you created in the pre-lab (insert it below.) (Each group member should count at least one field of view.)

  3. Repeat the step 3 three times with a new field of view each time.


ANALYSIS:

  1. Calculate the percentage of time the cells spent in each stage of the cell cycle for each field of view independently.  Create a new table to hold this information (insert it below.)

  2. Now sum the numbers from all four data sets and use the totals to calculate the percentage of time the cells spent in each stage of the cell cycle.  Place this data in the same table as the data from question 5.    Insert table below.

  3. Compare the time the cells spent in each stage of the cell cycle from the summed data to that from the individual data.  Do you notice any differences?


STANDARD DEVIATION CALCULATIONS:

Standard Deviation Equation
An important part of validating data is determining how repeatable the data is.  A simple way to examine repeatability is to look at the variability of the data. One way to calculate this variability is by using a standard deviation calculation. The equation to calculate standard deviation is shown to the left. 

This equation is actually quite simple.  In this case, n is the number of samples (number of fields of view you counted), Xi is one of the numbers in your data set (one field of view), μ is the average of the numbers in the data set (average of all field of views), and Σ means you sum the numbers.

As an example, suppose we had four numbers 1.0, 2.0, 3.0, & 4.0.  The average of these numbers is 2.5.  Therefore the standard deviation of this set is:



  1. In the above example of a standard deviation calculation, your calculator would have displayed the result as 1.11803398…  Why did we only display 1.1 as the answer?

  2. Calculate the standard deviation for each of your cell stages.  List the length of time each cell spends in each cell spends in each stage of the cell cycle with its standard deviation below using this format:  time in stage +/- standard deviation.

 

EXERCISE 3: Growth in the onion root.

 

PRE-LAB:

 

In this exercise we are going to study the growth of the onion root.  Growth can be effected by both the number of cells and the size of the cells.  You will look at four areas of the onion root the tip, one each in: the cap cells, the meristeam, the elongation region, and the maturations region. In each region you will determine the length of the cells and the percentage of cells that are in any stage mitosis (often called the mitotic index).

 

PRE-LAB QUESTIONS:

 

  1. Based on your knowledge of the cell cycle, what kind of relationship do you think you will see between cell size and the mitotic index?

  2. Using the If . . . Then . . . format, rewrite your answer to the questions in the form of a hypotheses.

  3. Create a table to record your data.  Insert the data table below.


DATA COLLECTION:

     
  1. Select the onion root tip slide (Slide Cassette 1: #8) using the RWSL microscope control.  (Each member of the group should collect data from a region)

  2. Position the microscope so that you are looking at the cap cells (see Figure 5:  Onion Root Tip for a refresher.)

  3. Count all the cells in the field of view; count how many of them are in mitosis.

  4. Determine how long each cell is.

  5. Position your sample so that you are looking at the meristeam and repeat steps 4  and 5.

  6. Position your sample so that you are looking at the elongation region and repeat steps 4 and 5.

  7. Position your sample so that you are looking at the maturation region and repeat steps 4 and 5.


ANALYSIS:

  1. Calculate the mitotic index for each region.  Modify your table from question one and enter the mitotic index in your new table.

  2. Calculate the size of the cells for each region and record that in your table from question 11.  The total field of view for your microscope is 305µm at 40X and 205µm.  Insert your data table below.

  3. How does your prediction of the relationship of the mitotic index to cell size correlate to the data you collected?

  4. If needed, rewrite your hypothesis in light of the new data you collected.

  5. Based on your observations and pre-lab reading, what stage of the cell cycle are the onion root cells  in the elongation region likely in?

 

EXERCISE 4: Stages of Meiosis.

 

PRE-LAB:

 

Observing the different stages of meiosis is often difficult do to the structure of the organs in which meiosis and fertilization occur.  One way scientist gets around this type of problem is through the use of model organisms. A model organism is an organism in which a particular biological process is easily observed or manipulated.  Two examples of model organisms used in the study of meiosis are the grasshopper testis and the Ascaris lumbricoides ovary.  The reason that these are good model organisms for the process of meiosis is that meiotic cells travel down the organ in a liner path.  Later stages of meiosis are farther along in the organ than earlier.  For example in a grasshopper testis it is often possible to observe all stages of both meiosis I and meiosis II.  The ovary of the Ascaris lumbricoides (a nematode worm) is similarly arranged. However, in the case of the Ascaris lumbricoides ovary you can see the polar bodies produced during oogenesis as their life time is long enough that they are preserved in the fixed tissue.  Additionally, fertilization also occurs in the ovary allowing for the observation of the pronuclei in early fertilization.  In this lab we are going to use these two model organisms to observe the processes of meiosis and fertilization.

 

PRE_LAB QUESTIONS: 

 

  1. Why are we not using human ovaries and testis to observe meiosis and pronuclei?


DATA COLLECTION:

  1. Select the grasshopper testis slide (Slide Cassette 1:  #12) using the RWSL microscope control panel.

  2. Use the "capture image" feature on the RWSL control panel to capture an image of the testis.

  3. Select the Ascaris lumbricoides Female slide (Slide Cassette 1:  #11) using the RWSL microscope control panel.

  4. Use the "capture image" feature on the RWSL control panel to capture an image of a developing oocyte with a polar body attached.

  5. Use the "capture image" feature on the RWSL control panel to capture an image of a fertilized egg with an egg and sperm pronuclei.


ANALYSIS:

  1. Use the insert and textbox feature on your computer word processing program to label two cells in meiosis I and two cells in meiosis II.  (Place Image Below)
  2. Use the insert and textbox feature on your computer word processing program to label the oocyte, polar bodies, and egg and sperm pronuclei as appropriate in the two Ascaris lumbricoides pictures. (Place Image Below) 

 

EXERCISE 5: Meiosis in humans (optional).

 

PRE-LAB:

 

In humans meiosis occurs in special tissues in specialized organs, the ovary in females and the testes in males. The biological function of these organs is to isolate, protect, support, and deliver the gametes.  Early in the process of development the cells that will become the gametes temporally exit the cell cycle and are segregated to a region of the embryo that will become the testes or ovaries. This process of segregation helps protect the DNA of germline cells from damage in two ways.  The first is that these cells will undergo fewer rounds of division and therefore DNA synthesis then the other cells in the body. This is important because DNA synthesis is one of the most common ways DNA modification can occur. Second these cells live inside the structure of the testes or ovary and get some protection from the outside world.  In this exercise we will observe the cells needed to support the development of the sperm and eggs in humans in this exercise. In addition to identifying fully developed sperm and eggs.

 

PRE-LAB QUESTIONS:

 

  1. Do you think the appearance of the chromosomes will look different in the meiotic cell cycle stages than in the mitotic cell stages you observed earlier?  Explain.


DATA COLLECTION:

  1. Select the prepared slide of the Mammal Graafian Follicles (Slide Cassette 1: #9) using the RWSL microscope control.

  2. Use the "capture image" feature on the RWSL microscope control panel to capture an image of the Mammal Graafin Follicles.

  3. Select the prepared slide of the Human Testis (Slide Cassette 1: #8) using the RWSL microscope control.

  4. Use the "cpature image" feature on the RWSL microscope control panel to capture an image of the Human Testes.


ANALYSIS:

  1. Use the insert and textbox features on your computer word processing program to label the primary follicle, primary oocyte, secondary follicle, and secondary oocyte (include it below.)

  2. Use the insert and textbox features on your computer word processing program to label seminiferous tubules and mature tailed sperm (include image below.)

  3. Was your prediction in question on correct?  Explain.

 

SUMMARY QUESTIONS:  Mitosis and Meiosis Experiment

 

  1. Which is more similar to mitosis:  meiosis I or meiosis II?  Explain your answer.

  2. Can a haploid cell undergo meiosis?  Can it divide by mitosis?

  3. Why do you expect the diploid number of chromosomes always to be an even number and never an odd number?

  4. How does crossing over contribute to genetic variability? Does this have any evolutionary significance?

  5. How does the cell decide which homologue goes to which pole during anaphase I?  How does this contribute to genetic variability?

 

PREPARING FOR THIS NANSLO LAB ACTIVITY:

 

Read and understand the information below before you proceed with the lab!

  

Scheduling an Appointment Using the NANSLO Scheduling System

 

Your instructor has reserved a block of time through the NANSLO Scheduling System for you to complete this activity. For more information on how to set up a time to access this NANSLO lab activity, see www.wiche.edu/nanslo/scheduling-software.  

 

Students Accessing a NANSLO Lab Activity for the First Time

 

You must install software on your computer before accessing a NANSLO lab activity for the first time. Use this link to access instructions on how to install this software based on the NANSLO lab listed below that you will use to access your lab activity – www.wiche.edu/nanslo/lab-tutorials.

 

  1. NANSLO Colorado Node -- all Colorado colleges.
  2. NANSLO Montana Node -- Great Falls College Montana State University, Flathead Valley Community College, Lake Area Technical Institute, and Laramie County Community College.
  3. NANSLO British Columbia Node -- Kodiak College.

 

Using the Microscope for a NANSLO Remote Web-based Science Lab Activity

 

We've provided you with three ways to learn how to use the microscope for this NANSLO lab activity:

 

  1. Read these instructions.
  2. Watch this short video. 
  3. Print off these instructions to read (PDF version of the instructions.)



NOTE:   The conference number in this video tutorial is an example.  See “Communicating with Your Lab Partners” below to determine the toll free number and pin to use for your NANSLO lab activity.

 

MICROSCOPE RWSL LAB INTERFACE INSTRUCTIONS

 

The Remote Web-based Science Lab (RWSL) microscope is a high quality digital microscope located at the NANSLO Node.  Using a web interface as shown below, you can control every function of the microscope just as if you were sitting in front of it. 

 

The equipment control software shown below is written using the LabVIEW software from National Instruments. The user interface is presented as a LabVIEW control panel which will be referred to as the lab interface for the remainder of the document.

Figure 1:  RWSL Microscope Lab Interface
Figure 1:  Remote Web-based Science Lab (RWSL) Microscope Lab Interface

 

COMMUNICATING WITH YOUR LAB PARTNERS

 

As soon as you have accessed this lab interface, call into the toll free conference number shown on the control panel to communicate with your lab partners and with the Lab Technicians.  Use the PIN code noted to join your lab partners.  Only one person can be in control of the equipment at any one time so talking together on a conference line helps to coordinate control of the equipment and creates a more collaborative environment for you and your lab partners.

 

GAINING CONTROL OF THE MICROSCOPE

 

Right click anywhere in the grey area of the lab interface and choose “Request Control of VI” from the dialogue box that appears when multiple students are using the microscope at the same time,.  After you request control, you may have to wait a short time before you actually receive control and are able to use the features on this lab interface.

 

Figure 2:  Right click anywhere in the grey area to "Request Control of VI" 

Figure 2:  Selecting "Request Control of VI"

 

RELEASING CONTROL OF THE MICROSCOPE

 

To release control of the microscope so that another student can use it, right click anywhere in the grey area of the lab interface and choose "Release Control of VI" from the dialogue box that appears. 

 

 

Figure 3:  Right click anywhere in the grey area and select "Release Control of VI" to release control of the lab interface

Figure 3:  Selecting "Release Control of VI" 

 

MICROSCOPE CONTROLS

 

 The Stage Controls allow you to adjust the visual of the specimen that has been placed on the stage of the microscope, select lenses with various magnifications, and select whether or not the condenser lens is in the light beam.  Below are more specific instructions on using these controls.  When using the arrows on this lab interface, click and hold the arrow until the desired effect is achieved or click and wait to view the result before clicking again. Quick clicks on the arrows may cause the system to lock up.

 

Figure 4:  Microscope controls including stage controls, objectives and condenser

Figure 4:  Microscope Controls - Stage, Objective & Condenser

 

Stage Controls: Using the left and right and up and down arrows found to the right of the microscope image in the Stage Control area, moves the microscope stage which holds the specimen.  These arrows allow you to precisely control the position of the specimen on the stage. 

 

  1. Use the "Right" and "Left" arrows to move the Stage so that you can view the specimen from left to right.
  2. Use the "Backward" and "Forward" arrows to move the Stage so that you can view the top, middle or bottom of the specimen.
  3. Use the "Up" and "Down" arrows to move the stage closer or farther away from the objective lens to bring a specimen into focus.   BE CAREFUL!  Don't move the stage too close to the lens.

 

When selecting the button between the "Up" and "Down" arrows, you can toggle between “Coarse” and “Fine” focus.  When the button is dark green and “Coarse/Fine” is displayed to the right of the button, the microscope is in “Coarse” focus.  When the button is bright green and “Fine” is displayed, the microscope is in “Fine” focus.   Typically, you will start with coarse focus which moves the stage in large increments and then use fine focus to complete your final focusing as it moves the stage in smaller increments.  There is no difference between the course and fine focus when using the 60X objective

 

NOTE:  When you click on these arrows, the specimen appears to move in the opposite direction.  Since the objective stays fixed, the image moves in the opposite direction of the stage.  This is how these controls work on most microscopes so the "feel" of the microscope is preserved over the web.

 

 

Figure 5:  Right/Left & Backward/Forward Stage Controls

    Figure 5:  Right/Left & Backward/Forward Stage Controls

    Figure 6:   Up/Down Stage Control & Coarse/Fine Focus Control       Figure 6:  Up/Down Stage Controls &
      Coarse/Fine Focus Control

                        

Objective:  A microscope mounts an objective lens very close to the object to be viewed.  Depending on need, different lenses with different power will be used on the microscope. This microscope feature multiple objectives, each with different power, mounted on a rotating turret.  The larger the magnification numbers the greater the magnification.  For example, if a specimen is viewed through a 40X objective lens, the magnifier in that lens displays the specimen 40 times larger than an equivalent view as seen by the unaided eye.  Remember that the ocular or other lenses also add to the magnification.

 

This microscope has five lenses – 4X, 10X, 20X, 40X, and 60X.  Use the arrows below the objective lens box that indicates the magnification of the current objective lens to move to a higher or lower magnification lens.  If you have activated the “Picture-in-Picture” Preset 2 (see below) you will be able to see the objective lens move when you select a new magnification.

 

Condenser:  The condenser controls whether or not the condenser lens is in the light beam. You want to have the condenser OUT for the 4x objective but IN for all the others.

 

SELECTING A CASSETTE AND LOADING SLIDES ONTO THE STAGE

 

There are two tabs on the lab interface.  When you first access the lab interface, the "Microscope" tab is displayed by default.  Click on the Slide Loader tab at the top of the screen to access the controls for the Slide Loader robot.  There can be up to four cassettes available on the Slide Loader.  These cassettes are used to store slides, and each can hold up to 50 slides.  The cassettes available to you are dependent on the lab activity to be completed.  Once a cassette has been selected, you will use the drop-down list to select your slides.

 

Figure 7:  Slide Loader Tab
Figure 7:  Select the Slide Loader Tab to select a cassette and slides.

 

 

EXAMPLE OF HOW TO LOAD SLIDES

 

In this example, we have selected Cassette #1. Using the drop-down menu, we have selected "1:  Colored Threads Whole Mount."  Then, we selected the "Load" button.  A message indicates that the slide is loading.  Using the picture-in-picture camera, you can watch this happening.  The robotics selects the slide and places it on the microscope stage.

 

Figure 8:  Selecting 1: Colored Threads While Mount Slide
Figure 8:  Selecting the slide
"1: Colored Threads Whole Mount" from Cassette #1

 

Notice that when a slide is actually on the microscope (or when it is being loaded or unloaded), the cassette controls are greyed out so you cannot load a second slide until the first is removed.  Once the slide is on the microscope stage, it will be listed in the "Current Slide on Stage" box.  The only thing that the Slide Loader robot can do is return it to the cassette when the "Return Slide to Cassette" button is selected. 

 

Figure 9:  Slide is loaded and Slide Loader Slide Selector is greyed out
Figure 9:  "LOADING SLIDE ... PLEASE WAIT" is displayed
in the "Current Slide on Stage" window

 

Select the "Microscope" tab to perform the NANSLO lab activity.  Once you are finished with the slide, select the "Slide Loader" tab and select "Return Slide to Cassette" button.  Once the slide is returned to the cassette, the Slide Loader controls are again available to select another slide from the cassette.

 

ENHANCING THE MICROSCOPE IMAGE

 

The digital camera mounted on the microscope has a camera control unit that is equipped with a series of image processing functions that enable you to quickly and easily correct imaging problems that arise from low or high contrast, poor focus, insufficient or uneven illumination, sample shading or discoloration and noise.  The most common reason for uneven elimination is a light source that does not completely fill the field of view on lower magnifications.  The White Balance should be used only if the image appears to be brown or gray, and you think you might need to adjust it (although it won't hurt anything to click this button).


A choice of color modes can be selected in the Microscope Image area and are used to display the image in different color palettes in order to highlight certain features.  The default setting is "Normal."

 

Figure 10:  Microscope Image Effects

 

Figure 10:  Microscope Image Special Effects and Other Image Controls for Camera

 

Here is a description of each option:

  1. In the “Normal” mode, the sample is displayed in its true  colors.
  2. In the “Negative” mode, the sample is displayed in a color-inverted form, where red, green, and blue values are converted into their complementary colors. The technique is useful in situations when color inversion can be of benefit in exposing subtle details or in quantitative analysis of samples.
  3. In the “Blue Black” mode, the black portions of a grayscale negative sample are displayed in blue. This mode is often useful to reveal details in samples having a high degree of contrast.  The “Blue Black” filter can aid you in examining a wide spectrum of difficult samples.
  4. In the “Black & White” mode, a grayscale image of the sample is displayed.
  5. In the “Sepia” mode, a brown scale (black and white) image of the sample is displayed. Although typically this filter is of little utility, it can be employed to alter image color characteristics to improve the visualization of sample detail.
  6. At times, the sample may have an unacceptable color quality.  Use “White Balance” calibration to remove the color cast.  This process is often referred to as white balancing.
  7. Auto Exposure is on automatically.  You do not need to do anything with Auto Exposure unless you are adjusting the luminance.  If you are doing so, you should turn off Auto Exposure by clicking on the button.  The green light is now off.  Now adjust the luminance.  See explanation below.

 

Reference:  http://www.microscopyu.com/articles/digitalimaging/dn100/correctingimages.html

 

Auto Exposure is normally turned on, but you can turn it off if you want to play around with the brightness of the light source and not have the microscope camera automatically adjust it.  It is usually best, though, to leave it turned on. 

 

When you turn off the Auto Exposure, the button turns dark green.  Some new controls appear that let you turn the LED off or on, and also adjust the intensity of the light source.  The intensity of the light source can be increased or decreased manually with the dial that now appears next to the Objective control when Auto Exposure is turned off.

 

Figure 11:  When auto exposure is turned off, LED controls are available

Figure 11:  Additional controls available when Auto Exposure is turned off

 

 

CAPTURING AND SAVING A MICROSCOPE IMAGE

 

When the “Capture Image” button is pressed, a high-resolution image of what is currently in the field of view of the objective is captured.  While the image is being captured, the button will be illuminated bright green.  The capture is complete when the light turns off.  Be patient as this may take several seconds to complete.


 After the Capture Image light turns off, select the “View Captured Image” tab on the bottom of this control panel to view the image.

 

Figure 12:  Select the Capture Image button and then select the View Captured Image Tab

Figure 12:  Click the capture image button (#1), wait till the green light goes off,
and then select the View Captured Image tab (#2)

 

After opening this image through the View Captured Image tab, you will need to take a snapshot of it and save it to your computer.  There are several ways to do this, depending on your operating system.


WINDOWS:

  1.  Pressing the two keys ALT and Print Screen simultaneously will copy the active window into your computer clipboard.  Then you can past it into a document.
  2. Windows 7 and above has a Snipping Tool program under Programs/Accessories which can capture selected areas of the screen. 
  3. Right click on it and select "Copy" from the menu presented.  After right clicking and selecting Copy, just open a document and right click and select Paste.  You can either paste it directly into your lab report document or into another one for safe keeping until you use it later.  You can use drawing tools in your word processing editor to annotate this image so you can show your instructor that you know what you were suppose to be looking for!

 

Figure 13:  Right click and then select copy to paste the image into a document

Figure 13:  Right click and select Copy to paste the image into a document

 

MAC:

  1. Press these three keys simultaneously MAC Keys to capture image.  This will change your cursor icon into a little cross. 
  2. Now press the spacebar, and the icon becomes a camera.  Click in the image window you want to take a snapshot of, and it will save the image to a file on your desktop.

 

There are lots of free screenshot utilities you can also use to capture this image.

 

If you are familiar with saving a document to your computer, you also can select “Save Image As” from the pop-up menu,  give the image a name and then select a location on your computer where you want this image to be saved for future use. 

 

MICROSCOPE IMAGE VIEW WINDOW

 

The Image View Window displays the real-time video feed from the digital camera “looking through” the microscope. 

 

Figure 14:  Image View Window
Figure 14:  Image View Window

 

PICTURE-IN-PICTURE CONTROLS - CAMERA PRESET POSITIONS AND PAN-TILT-ZOOM CONTROLS

 

When you click on the "Picture-in-Picture" button, it turns bright green.  A second real-time video feed from another digital camera appears in the Image View Window.  The controls shown in Figure 15 are all operational when the Picture-in-Picture feature is selected. 

 

Figure 15:  Picture-in-Picture Image Controls

Figure 15:  Picture-in-Picture Image Controls

 

CAMERA PRESETS

 

There are six camera preset positions.

 

Figure 16:  Picture-in-picture Preset 1 and 6Figure 16:  Picture-in-picture Camera Preset 1 and 6 - Displays the microscope, microscope camera,
and a camera control unit projecting the sample on the Stage. 

 

 

 

 

 

 

 

 

 

 

Figure 17: Picture-in-picture Camera Preset 2Figure 17:  Picture-in-picture Camera Preset 2:  Displays a closeup of the objective lens.

 

 

 

 

 

 

 

 

 

 

 

Figure 18: Picture-in-picture Camera Preset 3Figure 18:  Picture-in-picture Camera Preset 3 - Displays a closeup of the camera control unit
projecting the sample on the Stage.

 

 

 

 

 

 

 

 

 

 

Figure 19:  Picture-in-picture Camera Present 4 

Figure 19:  Picture-in-picture Camera Preset 4 - Displays the microscope eye piece and
the camera mounted to the microscope.

 

 

 

 

 

 

 

 

 

 

Figure 20: Picture-in-picture Camera Present 5Figure 20:  Picture-in-picture Camera Preset 5 - Displays the Condenser Lens underneath the Stage that focuses the light on the sample.  The Condenser Lens controls the width of the beam.  In some instances you will want a tighter beam while in other cases you will want a broader beam to control the image quality.  This setting has been optimized for you.

 

 

 

 

 

 

 

 

PAN, TILT, ZOOM CONTROLS FOR PICTURE-IN-PICTURE

 

For each camera preset view, additional camera options are available. 

  1. Use the up and down arrows to tilt the camera up or down. 
  2. Use the right and left arrows to pan right or left.
  3. Use the left "Zoom OUT" arrow and right "Zoom IN" arrow to zoom out and in.


Figure 21:  Picture-in-picture Zoom Capability
Figure 21:  Picture-in-picture Camera - Example of "Zoom In" capability

 

 

For more information about NANSLO, visit www.wiche.edu/nanslo.

 

 

All material produced subject to:


Creative Commons Attribution 3.0 United States License 3  

 

 

US Department of Labor Logo
This product was funded by a grant awarded by the U.S. Department of Labor’s Employment and Training Administration.  The product was created by the grantee and does not necessarily reflect the official position of the U.S. Department of Labor.  The Department of Labor makes no guarantees, warranties, or assurances of any kind, express or implied, with respect to such information, including any information on linked sites and including, but not lim ited to, accuracy of the information or its completeness, timeliness, usefulness, adequacy, continued availability, or ownership.

 

 

 

 

 

Comments (25)

Paul.Bennett@cccs.edu said

at 10:35 pm on Oct 28, 2013

Page 1: Learning Objectives #5: potential change recognize the processes of meiosis and describe the differences between mitosis and meiosis.

Paul.Bennett@cccs.edu said

at 10:36 pm on Oct 28, 2013

"Schwann: is not spelled correctly under Background Information.

Paul.Bennett@cccs.edu said

at 10:37 pm on Oct 28, 2013

Fixed

Paul.Bennett@cccs.edu said

at 10:38 pm on Oct 28, 2013

Page 2: Paragaph 3, sentence 1: take out "the."

Paul.Bennett@cccs.edu said

at 10:40 pm on Oct 28, 2013

Fixed

Paul.Bennett@cccs.edu said

at 10:38 pm on Oct 28, 2013

Fixed

Paul.Bennett@cccs.edu said

at 10:41 pm on Oct 28, 2013

Page 4: Define and differentiate between haploid and diploid cells.

Paul.Bennett@cccs.edu said

at 12:10 am on Oct 29, 2013

I added a few sentences about haploid and diploid cells.

Paul.Bennett@cccs.edu said

at 10:42 pm on Oct 28, 2013

Page 6: Equipment: add calculator.

Paul.Bennett@cccs.edu said

at 12:18 am on Oct 29, 2013

I left out the calculator intentionally. We should be encouraging the students to do their work with the equipment and methodologies they would use in a lab or job. The students should be using spreadsheet software (excel or Google Spreadsheet). I am happy to add appendix instructions on using spreadsheet programs if people think this is useful.

Paul.Bennett@cccs.edu said

at 10:42 pm on Oct 28, 2013

The students should have a folder open on their computer to save the captured images. Add instructions on how to do so.

Paul.Bennett@cccs.edu said

at 11:45 pm on Oct 28, 2013

We will add these instructions to the general interface instructions for all the microscope. That way they will be added to all microscope labs.

Paul.Bennett@cccs.edu said

at 10:43 pm on Oct 28, 2013

There should also be a sub-heading of "Testing Your Computer," Albert has a link/info. on how to do that and this should be included.

Paul.Bennett@cccs.edu said

at 11:50 pm on Oct 28, 2013

With our new interface there really is not any testing to do. The only thing the students will need to do is download the Citrix plug-in.

Paul.Bennett@cccs.edu said

at 10:48 pm on Oct 28, 2013

Page 7: #3 instructions should be provided on how to capture the image and send it to the students computer.

Paul.Bennett@cccs.edu said

at 11:16 pm on Oct 28, 2013

See the previous question about the image folder/instructions.

Paul.Bennett@cccs.edu said

at 10:50 pm on Oct 28, 2013

Last paragraph, sentence 2: define fixation.

Paul.Bennett@cccs.edu said

at 11:06 pm on Oct 28, 2013

I added a few sentences about fixation.

Paul.Bennett@cccs.edu said

at 11:26 pm on Oct 28, 2013

Page 8: Procedure: We should provide the table as an Appendix A. This will help the students to understand what they are looking for and to keep them on track.

Paul.Bennett@cccs.edu said

at 12:37 am on Oct 29, 2013

I did not include tables intentionally. If we are going to stick with level 2 in the Laboratory Openness document then we should not give the students the tables. The students need to think about the tables and should have the chance to fail.

Paul.Bennett@cccs.edu said

at 11:28 pm on Oct 28, 2013

Page 9: Exercise 3: sentence two "...four areas of the onion root tip, one each in:"

Paul.Bennett@cccs.edu said

at 11:40 pm on Oct 28, 2013

Fixed

Paul.Bennett@cccs.edu said

at 11:29 pm on Oct 28, 2013

This lab is fine for biology majors, however, a lot of our students' are in Medical Coding and/or are non-science major. I would like to alter the lab for the non-science majors for the purposes of my own class.

Paul.Bennett@cccs.edu said

at 11:34 pm on Oct 28, 2013

All faculty can modify protocols for their class as they wish.

Paul.Bennett@cccs.edu said

at 12:48 am on Oct 29, 2013

Fixed

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