| 
  • If you are citizen of an European Union member nation, you may not use this service unless you are at least 16 years old.

  • You already know Dokkio is an AI-powered assistant to organize & manage your digital files & messages. Very soon, Dokkio will support Outlook as well as One Drive. Check it out today!

View
 

Membrane Diffusion - NANSLO Lab Activity

Page history last edited by Sue Schmidt 9 years, 8 months ago

NANSLO REMOTE LAB ACTIVITY

 

SUBJECT SEMESTER: XXXXXXXXXXXXXXXXXXXXX

TYPE OF LAB:  XXXXXXXXXXXXXXXXXXXX

 

 

 

 

 

 

 

TITLE OF LAB:  Membrane Diffusion

 

Membrane Diffusion NANSLO Lab Activity in Word format last updated July 10, 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 of transport/diffusion.

 

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 - Spectrophotometer, Secondary - Cuvette Holder.

 

CONTENTS FOR MEMBRANE OSMOSIS LAB:

 

Learning Objectives

Background Information

Equipment

Experimental Procedure

Pre-lab Questions

Using the Remote Web-based Science Lab (RWSL)

Exercise 1:  Diffusion

Summary Questions

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. Explain why some molecules can pass through a membrane as the result of diffusion.
  2. Relate the concept of concentration gradients to molecular movement.
  3. Determine what is being measured in a spectrophotometer, and explain the basics of spectrophotometry.
  4. Explain how temperature impacts molecular movement.
  5. Collect quantitative data on the rate of diffusion at different temperatures.
  6. Graph the data collected and interpret the data.
  7. Determine the effect of temperature on the diffusion rate of iodine through a dialysis tube membrane.

 

BACKGROUND INFORMATION:

 

Figure 1: Diffusion of small uncharged molecules across the plasma membrane.This laboratory activity will focus on the transport of molecules via diffusion. In a living system, this can take place across a semipermeable membrane or it can take place within the cytosol or through extracellular fluid.  The life of a cell is dependent on efficiently moving molecules into and out of the cell, and a factor of this movement is the cell membrane.  Molecules which are small and uncharged are able to move easily across the cell membrane (lipid bilayer) in a process known as simple diffusion. Molecules in living things move in a variety of ways but for the purpose of this lab the focus will be on simple diffusion.  The process of simple diffusion relies on the inherent nature of molecules to move from high concentration to lower concentration. 

 

The structure of the plasma membrane is a semipermeable lipid bilayer.  The phospholipid molecules form a “sandwich” with the hydrophilic portion of the molecule in contact with the internal cytosol and the external extracellular fluid. The hydrophilic fatty acid tails are in the center of the sandwich.  The membrane system in a cell is fluid so the phospholipid molecules themselves can move, and small uncharged molecules can move into and out of the cell.  See Figure 1.

 

Figure 2: Positions of atoms in a solid, liquid, and gas.It is important to understand some basics of molecular vibrational movement since the molecules continually move against each other.  Atoms and molecules are in constant motion, even in a solid state, the molecules exhibit vibrational movement as they move against each other in position. When molecules are in a liquid state, they can be farther apart than in a solid, but not nearly as far apart as in a gas.  See Figure 2.

 

Because molecules are in constant motion, the molecules are colliding with each other. This type of motion is called Brownian movement. It can be defined as the irregular motion of small particles suspended in a liquid or gas, caused by the bombardment of the particles by molecules of the medium1.

 

To better visualize the effect of temperature on Brownian movement, watch the following simulation: States of Matter (http://phet.colorado.edu/en/simulation/states-of-matter-basics.)  On the “Solid, Liquid, Gas" tab, set Atoms and Molecules to “water” and set Change State to “liquid.”  Then simply change the temperature control to either “cool” or "hot." As you do this, notice changes to both the rate of molecular movement and the distance between the molecules.  You can also investigate how phase changes occur on the Phase Changes tab.

The process of simple diffusion in cells is a process of passive movement meaning that there is no outside energy applied to the system which impacts the molecular motion.  Passive transport is any type of transport of molecules that does not require any additional energy.  It takes place solely based on the inherent molecular movement of Brownian motion.  The process of simple diffusion is slow over macroscopic distances and impacted by the types of molecules present as well as by the temperature.  Think for a minute about a drop of food coloring in a glass of water.  If the water is hot, the water molecules will be moving faster, and the collisions with food coloring molecules will be more frequent causing the food coloring to diffuse more rapidly.  On the other hand, ice water will have the opposite effect.  Think back to the states of matter simulation.  Could you see a difference in the rates of molecular movement between the different states (solid, liquid, and gas)?  Now imagine if there were several different types of molecules in the glass.  All of these molecules would be colliding with one another like too many people in a room making it harder to get from point A to point B.


Diffusion is the movement of molecules from a place where the molecule is in higher concentration to a place where that molecule is less concentrated.  Equilibrium is when there is no longer a net movement in one direction.  Concentration gradient is the difference in the concentration of the molecules over a distance.  Diffusion of particles can take place between two fluids separated by a membrane or within a fluid where a concentration gradient exists. 

 

Figure 3: Components of a spectrometer.There are both qualitative and quantitative methods that can be used to record and observe diffusion. Qualitative data are based on the 5 senses: what does it look like, smell like or feel like? Quantitative data on the other hand are measured and numerical.  In this lab, we will be using a spectrophotometer to quantitatively measure the rate of absorbance as it changes.

 

Absorbance measurements are used to quantify the concentration of gases and solutions that absorb light in a medium that transmits light. The signal in absorbance units is proportional concentration of the sample.  From the change in the absorption values, we can then calculate the rate of diffusion.  The rate of diffusion is a measurement of some variable over time.  In this case we will be looking at:  [Rate of Diffusion = Change in Absorbance/Time]. The independent variable in this experiment will be time.  You will have three temperature variables.

 

How a Spectrophotometer works: In Figure 3, you can see the basic components of a spectrophotometer and how the spectrophotometer works. The light source will provide all wavelengths of visible light and wavelengths in the ultraviolet and infrared range as well. The light enters the spectrophotometer through a fiber optic port and some filters (1, 2 and 3 in Figure 3) and hits a series of mirrors and diffraction gratings (4, 5 and 6) which act to separate the light into its wavelengths.  The separated wavelengths are then focused through some lenses (7) onto the detector array (8) simultaneously.  The detector then sends its data to some other electronics (9 and 10), which turn the signal into the spectrum graph that you see on your computer.

The spectrophotometer setup you will be using is shown in Figure 4.  

 

Figure 4:  Equipment set up.

The robotic syringe pump will contain the iodine solution.  You will be able to deliver this solution through a needle directly into the top of a cuvette containing a diffusion membrane insert.  See Figure 5. 

Figure 5: Cuvette with diffusion membrane.  

 

A close up of the needle is shown in Figure 6.

 

   Figure 6:  Close up of needle.
 
The cuvettes will be pre-loaded with starch solution (clear) and a small stir-bar to stir the solution.  You will be able to select a cuvette by rotating the carousel.  You will deliver a small, pre-measured amount of iodine solution (red-brown) with the robotic syringe pump, and it will begin moving through the diffusion membrane into the starch solution and will react chemically with the starch to form a starch-iodine complex (blue-black).  You can detect the formation of this new chemical by how much light of a specific wavelength that it absorbs.  You will be able to control the temperature of the cuvette carousel so you can see how different temperatures affect the rate of diffusion.  There are six cuvettes in the carousel, so you will have up to six opportunities to measure diffusion rates.

Sources:

 

Brownian Movement:  http://dictionary.reference.com/browse/brownian+movement
Simulation: http://phet.colorado.edu/en/simulation/states-of-matter-basics
Figure 3: http://www.oceanoptics.com/Products/benchoptions_usb4.asp

 

EQUIPMENT:

 

  • Paper
  • Pencil/pen
  • Computer with Internet access (for the remote laboratory and for data analysis)

 

EXPERIMENTAL PROCEDURE:

 

Read and understand these instructions BEFORE starting the actual lab procedure and collecting data.  Feel free to “play around” a little bit and explore the capabilities of the equipment before you start the actual procedure.

 

 

PRE-LAB QUESTIONS:

 

From the background reading you have an understanding of the inherent movement of molecules and how temperatures increases or decreases can cause a change in the rate of molecular movement.  In this lab, you will follow the rate of diffusion as a function of temperature.

 

  1. What pattern do you think you will see in the rate of diffusion as temperature changes?  Explain answer.
  2. Hypothesis/Prediction -- Set this up as an if . . . then . . . statement.  For example: If heat is applied to particles in random motion then observable differences will be seen in the movement at the different temperature.  This example is meant to be very general.  Your job is to use your answer to question #1 and make it into a more specific if-then statement based on your understanding prior to observing the slides.
  3. Create a data table for the temperature, time, absorbance, and rate of diffusion. 

 

USING THE REMOTE WEB-BASED SCIENCE LAB (RWSL):

 

If you are not already familiar with how to use the remote spectrometer for this experiment, refer to the section called Preparing to use the Remote Web-based Science Lab (RWSL).  

 

EXERCISE 1:  Diffusion

 

Data Collection:

 

From the Spectrometer Tab:

 

  1. Click on the "Start" button to start the spectrophotometer data feed.
  2. Ensure that the spectrophotometer light is turned off.
  3. Set "# Spectra to Average" to a value of 20.
  4. Store a dark spectrum. 

 

From the Cuvette Holder/Temp Control/Display Tab

 

  1. Turn on the Temperature Controller and select an initial temperature of 20°C.
  2. Ensure that the stirrer is turned on so the solutions are being mixed.  (Use camera preset 2 to verify that the Cuvette Holder controller screen says "Stir On."
  3. Wait until the temperature has been stable for at least 2 minutes.

 

From the Spectrometer Tab:

 

  1. Turn on the spectrophotometer light.
  2. Store a reference spectrum.
  3. Select the "Show Absorbance Spectrum" button to view the absorbance spectrum and Zoom Out on the graph.
  4. Turn on the cursor and drag it to 351.8 nm.  This is where an absorbance peak will appear when the starch-iodine complex forms.

 

From the Spectrometer/Value Log Tab

 

  1. Ensure that "Minutes to Collect" is set to 10 minutes and "Collect Every (x) seconds" is set to 30 seconds.

 

From the Cuvette Holder/Cuvette Select and Volume Tab

 

  1. Select Pump #1 and ensure that "Volume to be Added"
  2. Click the "Add Volume" button and observe the volume in the cuvette increasing from 3.75 to 4.0 ml as the iodine solution is added.

 

From the Spectrometer/Value Log Tab

 

  1. Click Start.
  2. Time and Absorbance data will not be collected every 30 seconds for 10 minutes.
  3. You can watch the absorbance peak grow on the Spectrometer Tab.
  4. Value Log data to the clipboard and paste it into a document.

 

From the Cuvette Holer/Cuvette Select and Volume Tab

 

  1. Select another cuvette on the "Cuvette Selector" tab to start with a clean starch solution.
  2. Another student should take control of the control panel at this point.
  3. Set the temperatore to 30°C.
  4. Start over with step 2 and collect another set of data.
  5. Another student should now take control and set the temperature to any setting between 30°C and 50°C.
  6. Start over with step 2 and collect another set of data.
  7. If there are students who haven't collected any data, and there is time remaining in your lab period, collect more data sets if you would like.  Do not exceed 50°C!

 

Analysis (can be done offline):

 

  1. Using the Value Log data, create a graph. On the graph you will plot time as the independent variable and absorbance as the dependent variable. You should have three different lines for the three temperature variables (or more if you collected more data).
  2. Analyze the graph by relating the shape of the curve to an underlying mechanism that might govern the phenomenon being studied. Discuss factors involved in diffusion that might cause this curve shape to be true.  
  3. Calculate the rate of absorbance change for each of the temperatures with the following equation: Rate of Diffusion = Change in Absorbance/Time, add these values to your data table.
    1.  With your graphed data, calculate the slope of the line for the last 5 minutes of the data collected at each temperature. Slope is calculated by first choosing two points on the graph then determining the change in the horizontal points and the change in the vertical points. For example if your coordinates on the graph at point #1 are 0.5 (x axis) and 6 (y axis)and at point #2 the coordinates are 4 (x axis) and 12 (y axis). So the vertical change is 12 - 6  and the horizontal change is 4 – 0.5 or vertical change = 6 and horizontal change = 3.5.  To find the slope, you would divide the vertical change by the horizontal change. 6/3.5 for a slope of 1.7. The slope is the rate of diffusion.  Be sure to include the correct units for your data. Show your calculations and then plot on a graph the diffusion rate (slope of the last 5 minutes worth of data) vs. temperature. What information can you get from this graph?
    2. What information can you get from this graph?
  4. On your initial time versus absorbance graph, interpolate what the absorbance curve would look like at 25°C.
  5. On the highest temperature absorbance curve that you graphed, extrapolate out to 40 minutes – what do you think the absorbance would be at that point? Would the values continue to increase linearly? Explain your reasoning.

 

SUMMARY QUESTIONS:

 

  1. Research the following:
    1. What is kinetic energy and how does it differ from potential energy?
    2. What environmental factors affect kinetic energy and diffusion?
  2. Why do these factors alter diffusion rates? How do they affect rates?
  3. Compare the process of diffusion to osmosis. Would the effect of temperature on movement be the same in either type of transport? Why or why not?
  4. Membrane systems often have folds in the membrane which functions to increase surface area. Based on what you know about molecular movement explain why it is important for cells to have an increased surface area.
  5. For most freshwater organisms internal salt levels are maintained far above that of the outside water.
    1. Describe in which direction water will move for these organisms.
    2. Would this be an osmotic process or diffusion process explain your reasoning.
    3. Why could this be a problem and how might they deal with it?
  6. Think about the effect of temperature on molecular movement. For which temperature do you think there would be more molecular interactions? Use your observations to support your answer.
  7. Make a claim about what you learned and back it up with the data or evidence you gathered. You may have more than one claim and evidence statement.
  8. Think back to the initial hypothesis/prediction you made, was your prediction correct? Write a statement that uses your data to either support or reject your hypothesis.

 

PREPARING TO USE THE REMOTE WEB-BASED SCIENCE LAB (RWSL):

 

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.

 

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

 

  1. Read these instructions.
  2. View this short video:



  3. Print this PDF version of the instructions below.

 

SPECTROMETER LAB INTERFACE INSTRUCTIONS

 

The Remote Web-based Science Lab (RWSL) spectrometer is controlled remotely by using a web interface as shown below.  This lab interface allows you to  control every function of the spectrometer 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 7: Spectrometer lab interface

Figure 7:  Spectrometer lab interface

 

COMMUNICATING WITH YOUR LAB PARTNERS

 

As soon as you have accessed this lab interface, join the voice conference so you can communicate with your lab partners and with the Lab Technician.  Click the Yellow button for directions on how to use either your telephone or your computer microphone and speakers to participate in the voice conference.  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 SPECTROMETER

 

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 spectrometer at the same time,.  If you request control when someone else already has it, you will be placed into a queue and will receive control when the other person releases it.

 

Figure 8:  Take control
Figure 8:
  Take control of the lab interface by right clicking and selecting "Request Control of VI."

 

RELEASING CONTROL OF THE SPECTROMETER

 

To release control of the spectrometer 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 9:  Release control of the lab interface
Figure 9: 
Release control of the lab interface by right clicking and selecting "Release Control of VI."

 

ACTIVATING THE SPECTROMETER

 

To activate the spectrometer data feed, click the "Start" button on the far left portion of the lab interface. The button will now turn yellow and say “Pause”.

 

Figure 10:  "Start" changes to "Pause" when button is selected.

Figure 10:  "Start" changes to "Pause" when button is selected.

 

SPECTROMETER VIEW WINDOW

 

The Image view Window displays the real-time video feed from a digital camera focused on the spectrometer, the robotic syringe pump, the robotic cuvette holder, and the controller unit for the cuvette holder.

 

Figure 11:  Spectrometer (1), robotic syringe pump (2), robotic cuvette holder (3), and the controller unit for the cuvette holder (4).

Figure 11:  Spectrometer (1), robotic syringe pump (2), robotic cuvette holder (3), and the controller unit for the cuvette holder (4).

 

CAMERA PRESETS AND PAN-TILT-ZOOM CONTROLS

 

Several camera preset positions have been programmed for use with this lab interface.  Hovering over the gray area where the buttons are will give you a pop-up menu that describes where each preset is assigned to as shown in Figure 12. Images shown are representative of these functions and are not specific to this lab activity.

 

Figure 12:  Six Camera Presets
Figure 12:
  Six camera presets.

 

The four arrows used to pan and tilt allow you to move the camera right to left and up and down.  The two zoom buttons allow you to zoom in to see a closer look at the equipment such as shown in Figure 13 or zoom out to view more of the room.

 

Figure 13:  Pan, tilt and zoom capabiliites
Figure 13: 
Pan, tilt and zoom capabilities.

 

SETTING UP THE SPECTROMETER

 

You will need to store a dark spectrum and a reference spectrum before any absorbance data can be collected.  This is done by clicking Store Dark (with the spectrometer's light turned off) and then clicking Store Ref (with the spectrometer's light turned on and a clean cuvette selected.)

 

Figure 14:  Storing the Dark Spectrum.

Figure 14:  Storing the Dark Spectrum.

 

Figure 15:  Storing the Reference Spectrum.

Figure 15:  Storing the Reference Spectrum.

MANIPULATING THE SPECTRUM

 

You will now need to “zoom out” on the spectrum window to view the entire spectrum properly.  Here’s how to zoom in and out on the spectrum.  The images shown are representative of these functions and are not specific to this lab activity.

 

  1. Click on the center button at the lower right of the graph, shown below in Figure 16.

    Figure 16:  Click button to access other options.
                                      Figure 16:  Click button to access other options.

  2. This brings up a small sub-menu of other buttons.  The only two that are useful to you are the left-most buttons in the top and bottom rows.  Select the left-most button in the bottom row to view the entire spectrum.

    Figure 17:  Spectrum Zoom Out Button
                                                  Figure 17:  Spectrum Zoom Out Button

  3. Select the left-most button in the top row to select specific parts of the spectrum to “zoom in” on and view more closely (see Figure 18).  After clicking this button, you use the mouse to draw a box around the area that you want to zoom in to.  Be sure you draw the box so that it includes some area past the top of the peak you are interested in or else it will chop off the top of it in the viewing window. If you accidentally zoom in too far or on the wrong part of the spectrum, just zoom out and start over again.

    Figure 18:  Spectrum Zoom In Button
                                                     Figure 18:  Spectrum Zoom In Button

 

THE CURSOR CONTROLS

 

Make sure you are zoomed out to view the entire spectrum (Figure 18 above.)  Click the button labeled "Enable Cursor" under the left side of the graph.  The green light will come on, and a vertical green cursor line will appear on the screen.  Click the cursor control button.  Use the mouse to "grab" the cursor line by clicking on it and dragging it to the peak that you want to identify. You must have control of the lab interface to be able to do this activity.  The images shown are representative of these functions and are not specific to this lab activity.

 

Figure 19:  Click the "Enable Cursor" button and then the "Cursor Control" icon to move the cursor. 

Figure 19:  Click the "Enable Cursor" button and then the "Cursor Control" icon to move the cursor.

 

There are now two fields under the graph:  “Wavelength (nm)” and “Intensity”.  The Wavelength field shows the current position of the cursor, and Intensity shows a relative intensity reading of wherever the cursor is located (Figure 19).

Once you have the cursor on top of a peak, you can zoom in on it to make sure you are really on the highest part of the peak.  (Sometimes they are double peaks!) If you zoom in or out, you will need to click the cursor control button again in order to move the cursor.

 

If you want to zoom in on a peak for a closer look, make sure you place the cursor approximately on that peak before you click the "Spectrum Zoom In" button and draw a bar around it. 

 

If you lose the cursor while zooming in on peaks, just zoom out again to find it or turn it off and back on again, and it will appear in the center of the current spectrum.

 

EXPORTING A GRAPH OF THE SPECTRUM

 

Locate the" Export to Clipboard" button.  Go to the pull-down box to the right of it and set it to "Graph Image."  Now click the Export to Clipboard button which will place a copy of the spectrum in your clipboard.

 

IMMEDIATELY start a program like Paint or Word or PowerPoint and paste in the spectrum. Save the file with an appropriate name so you can find it later.

 

You must have control of the Control Panel to do this, of course. 

 

THE VALUE LOG

 

If you need to capture a set of values from the graph for a specific period of time, the Value Log tab allows you to do this easily (Figure 20.)  On this tab, you will see the current position of the cursor on the graph, which is where the data will be gathered from when you click the "Start" button on this tab.

 

You can also set the number of mintues that you want to collect the data and how often you want to collect data points by modifying the "Minutes to Collect" and "Collect Every (x) Seconds" fields.  You can start and stop the data collection as often as you like, and you can export the current Value Log to your computer's clipboard by using the button at the bottom of the screen.  After clicking the "Export Value Log to Clipboard" butt, you must IMMEDIATELY open a spreadsheet file and click Edit, Past (or press Ctrl V or command V) to paste the data into the spreadsheet.

 

You must have control of the Control Panel to do this of course.

 

After you have exported the data, you can clear the values and collect another set of data.

 

Figure 20: The Value Log tab.
Figure 20: 
The Value Log tab.

 

CONTROLLING THE CUVETTE HOLDER AND PUMPS

 

Clicking on the "Cuvette Holder" tab will give you access to the controls for this part of the system.  Preset 2 on the camera controls allows you to zoom in and see the results of the controls on the cuvette holder controller.

 

From the Temp Control/Display tab, you can turn the temperature control and the stirring control on or off.  You can also see a graph of the cuvette holder's internal temperature (Figure 21.)

 

Figure 21:  The Temp Control/Display Tab
Figure 21:
  The Temp Control/Display tab.

 

The Cuvette Select and Volume tab allows you to choose which cuvette is currently selected for analysis and also to fill that cuvette with various liquids, depending on the activity you are doing.  Only one pump may be selected at a time, and there may be up to two pumps available, depending on the activity (Figure 22.)

 

Figure 22:  Cuvette Select and Volume tab.

Figure 22:  Cuvette Select and Volume tab.

 

You can change the "Volume to be Added (mL)" number and click on "Add Volume" to deliver that amount of liquid from the selected pump into the currently selected cuvette.  You can watch this happen with Preset 4 on the camera controls (Figure 23).  The system will not allow you to overfill a cuvette, and you can see how full it currently is on this tab.

 

Figure 23:  Pump #1 is selected.
Figure 23: 
Pump #1 is selected.

 

The Ramp Controls tab allows you to set a temperature profile and run it on the cuvette holder.  This will not be used for most lab activities.  You can set up to 6 set points and how long to hold at each point  Clicking Start Temperature Profile will then rampe the temperature up and/or down through those points (Figure 24.)

 

Figure 24:  Ramp Controls tab.
Figure 24: 
Ramp Controls tab.

 

 

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 (0)

You don't have permission to comment on this page.