Describe how to make 10ml of a 125 dilution from a 1 times 1

Describe how to make 10ml of a 1:25 dilution from a 1 times 10^12 cells/ml stock. What is the resulting cell concentration?

Solution

= 1/25

Step 1

Take one part stock and add 4 parts water to get 1/5 dilution i.e. 1x 10 ¹² cells/ml/ 5

= 0.2 1x 10 ¹² cells/ml

Step 2

Now take one part stock of this cell suspension and add 4 parts water to get 1/5 dilution leading to 1/25 dilution.

= 0.2 x 10 ¹² cells/ml/ 5

0.04 xx 10 ¹² cells/ml the total volume will be 10 ml

b) = 4 x 10 ¹⁰ cells/ml       this is the final cell concentration.