Description
Distributed files
Materials
Other curricular elements
Ponderables
Random walk simulation
Lab: Brownian Motion
Lab: diffusion in gels
Sample Class plans
FAQs
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Motion of polystyrene beads -- Analyzing and capturing movies with LoggerPro
Bring the following pieces of equipment to your lab bench:
- Computer
- Microscope
- Microscope video capture kit
Let's get the video capture going:
- Boot up your computer
- Once it has started up, plug the USB capture device into the USB port (you may have to use the one on the back of the machine).
- Hook the camera up to the yellow plug and plug in the power supply
- Start logger pro
- Use the pull down menu to insert .. capture video
- You should get a new window. If you block the camera with your hand, the window should go from light to dark.
- If that works, capture a short video.
- Where is your video stored? You will need these later.
- Be sure to record file names, their content, and brief
descriptions in your notebook ... as well as the rest of your
proceedures here.
- Check your microscope calibration with the microscope
caliper. This is a metallized pattern of 10 micron and 100 micron
spaced lines. You will use the Levy-counting chambers for this lab.
Place several drops of water on each one and cover with a coverslip.
Now calibrate the grid of lines on the Levy chamber against the
microscope caliper. Repeat for all objectives up to 40x.
Collecting your data
- Once you have calibrated each objective on your
microscope, then you are ready to capture your own film clips of
brownian motion. Dry your Levy chamber and place a few drops of the 3
micron polystyrene sphere solution in it and a coverslip over the top.
Carefully place this on the microscope. Measure the size of your
spheres, film them, and quantitatively characterize their motion.
- Repeat this for .5 micron and 1 micron diameter spheres.
- Plot the position vs. time data in logger pro. How does it compare to the simulations done on Friday and for the warmup?
- Calculate the total distance traveled vs. time. Compare these data to the plots made in the 30 coin flips exercise.
- Repeat the above for bacterial samples. What can you conclude
about bacterial motion. Does it have a random component? A
deterministic component?
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