The depth of the hemocytometer sample box is 0.1mm for all questions.
Please show all calculations.
1. You count 74 cfu on a pour plate. The plate was prepared by spreading 0.2 ml of a 1:10,000 dilution of the original sample. What is the density of the original culture (in cells/ml)?
2. You have a culture of yeast that is at a density of 4.76 x 10^6 cells/ml. You dilute the sample 1:100, and then again 1:100, and finally you dilute the sample an additional 1:3. You add 0.1 ml of the final dilution to a spread plate. Assuming that most of the cells in the original culture were living, how many colony forming units do you expect to count on your plate the next day?
3. What is the average size of a yeast cell?