Purpose:

The purpose of this lab was to further practice our lab skills which include micropipetting, cell counts, using microscopes, taking samples, timing organisms, and begin the experiment. To observe the effects of the polypropylene on Tetrahymena’s behavior of the Tetrahymena from the control and treatment group in the swim speed assay.

Procedure:

1. Before beginning the lab, be sure your workstation is clean to avoid any hazards.
2. Then get 5 mL of the control solution and 5 mL of the treatment solution using a pipette gun.

Cell Counts:

1. Take your control and place three drops of 2 μl of Tetrahymena onto a flat slide.
2. Add 1 μl of iodine to each drop.
3. Place on the stage of a compound light microscope and begin counting the cells in each drop and record data. Be sure to work quickly because the droplets evaporate quickly.
4. Repeat steps 1 through 3 with the treatment test tube.
5. Calculate the number of cells.

Optical Wavelength:

1. Place the PPT test tube into the Spectrophotometer and calibrate to zero. Record value.
2. Take out the PPT test tube and replace with the treatment test tube into Spectrophotometer and record value.
3. Take out the treatment test tube and replace with the control test tube into Spectrophotometer and record value.

Swim Speed Assay:

1. Measure out 20μl of control solution and place onto a flat slide.
2. Turn on dissecting microscope and place the slide with a ruler under onto the stage.
3. Set up a timer and watch the Tetrahymena swim between the two marks on the ruler.
4. Choose one Tetrahymena and start the timer when ciliate crosses first line. Stop the timer when it crosses the second line and record data.
5. Repeat step 4 nine more times.
6. Repeat Steps 1 through 5 with the treatment solution.

Data: 

Cell Count-