Question

You notice that Alice wanted to check the cell number after one hour of growth, so she also used a Petroff-Hauser chamber (Hemocytometer) to count the number of cells. If she had
10^4 cells in the original culture tube after one hour, how many microliters (uL) of the original undiluted culture would she need to be able to count approximately 100 cells?

Answer 1

If the culture tube has 10^4 cells, she needs 100 cells or 10^2 cells, that means she has to take 10^4/10^2 = 100 times less volume of the original culture in which the cell number is 10^4. or she can dilute the original culture to 100 times to get 100cells.

Say 1ml (= 1000 uL) volume contains 10^4 cells, how much volume should contain 10^2 cells?

10^4 cells per 1000uL, so 10^2 cells per 10uL.

So if she takes 10uL of 1ml of the undiluted culture having 10^4 cells, she will get 100 cells.

Similarly if she takes 1uL of 100uL of the undiluted culture having 10^4 cells, she will get 100 cells.