Question

You want to prepare 500mL of LB broth containing 100 µg/mL of ampicillin. Your stock solution of ampicillin is at a concentration of 100 mg/mL. How many microliters of the stock solution of ampicillin will you add to the 500 mL of LB broth? Round your answer to the nearest microliter.

Answer 1

500 µL

Step-by-step explanation:

Total mass required of ampicillin:

• 500 mL * 100 µg/mL= 50000 µg ampicillin

• 50000 µg * 1mg/10³µg = 50 mg

The required volume V of the stock solution can be calculated by the formula:

Concentration * Volume = Mass

• 100 mg/mL * V = 50 mg

• V = 0.5 mL

Finally we convert mL into µL:

• 0.5 mL * 10³µL/1mL = 500 µL