Purpose: The purpose of this experiment is to further explore serial dilutions to find concentration of cells per mL.

Procedure:

1. Obtain 5 centrifuge tubes and label them -1 to -4.
2. Add 90uL of media into the tubes.
3. Add 10uL of tetrahymena to the tube labeled -1.
4. Add 10uL of tube -1 to tube -2.
5. Repeat step 4 for the rest of the tubes by adding 10uL from the previous solution into the next tube.
6. Place 5uL from each tube onto a concavity slide.
7. Count the number of tetrahymena from each tube on the slide and record observations.
8. Decide which tube was the best and place three more 5uL drops onto the concavity slide.
9. Count the tetrahymena and record observations.
10. Do calculations using standard deviation.

Data:

Conclusion: After we finished this lab, I have become more comfortable performing serial dilutions and micropipetting solutions. One error that my group and I did was that instead of using the media, we used water. This impacted our overall data.