
Calculations
The formula used to make our various dilutions was:
M1xV1 = M2xV2
M1 = stock concentration
M2 = final concentration
V1 = how much of the stock we need (the volume)
V2 = the volume of the treated cell culture well
For example: How do we make a working stock of 600 nM E2 (Estradiol)? We need to make 2 mL of the drug.
(10uM) (x) = (600nM) (2000uL)
(10uM) (x) = 12 x 10^6nM x uL
x = (1.2 x 10^6nM x uL) / 10000nM
x = 120 uL
To count the cells a hemocytometer was used. This is a glass slide with a chamber for counting cells within a given volume. The counting is done visually using a microscope, and four counts are done for each sample, or different treatment. These counts are then averaged, and the total number of cells is determined using the following formula:
Cells/mL = the average count x 10^4
Total Number of Cells = cells/mL x original volume from which sample was taken