Question

A culture of bacteria contains 10⁷ cells per mL. In order to inoculate a flask with 500 mL of media so the initial culture will have 6,000 bacteria per mL, how many mL of culture should be transfered?

Answer 1

1 ml has 107 cells per ml to get 6000 bacteria per ml

107 cells          in                     1ml

6000cells         in                     ?

6000*1/107   = 56.07ml

If you take 56.07 ml of 107 cells per ml solution that contains total 6000 cells.

Now add 56.07ml to 443.925ml of media so you will get total 500ml media with 6000cells/ml.