Question

To dilute a bacterial culture, 100 mu l of a 16 hour culture is mixed with fresh culture media to a final volume of 5 ml. The 16 hour culture was diluted by a factor of: _____ An antibiotic (ampicillin) used during a Transformation experiment. Ampicillin is stored as a stock solution of 100 mg/ml. You are pouring plates from a 500 ml flask of Lauria Bertini agar (LB Agar) and you need an antibiotic concentration of 100 mu g/ml in the plates. How many mu l of the antibiotic stock need to be added to the agar to get the desired concentration? _____ mu l need to be added

Answer 1

100 mul means 100 times 10^-6 litre or 100 times 10^-3 ml 0.1 ml rightarrow 5 ml 0.1 rightarrow 5 ml therefore dilution factor is 50.