Purpose:

• In this lab, the purpose of the lab was to make Tetrahymena solutions of a certain concentration and determine whether or not NaCl has an effect on the Tetrahymena population.

Procedure:

1. First, the resaerchers retrieved the Tetrahymena culture stock solution and PPT media.
2. 90 microliter of the PPT media  was added to 4 tubes each along with 10 microliter of the undiluted Tetrahymena stock.
3. The researcher then attempted to count the number of cells in the three different drops.
4. Sodium chloride was added to the concavity slides and the effects on the Tetrahymena was then observed by counting the number of cells that are currently present.

Result/Findings:

Conclusion:

• This lab, just like the previous one, emphasized the importance of using serial dilutions to calculate the number of Tetrahymena in the sample. Also, the researchers determined that the NaCl did not have an effect on the Tetrahymena population in the samples that were treated with NaCl.