Question

If you need to do a 1:20 dilution on a culture to get acceptable plate counts, how many milliliters of original sample will you add to a final volume of 0.1 mL?For this course, a 1:20 dilution is 1 part culture to a final volume of 20 parts.For example, 1 mL culture and 19 mL sterile DI water.Report your answer to 4 decimal places

Answer 1

Answer:

0.0050 mL

Explanation:

First we divide the final volume by 20:

• 0.1 mL / 20 = 0.005 mL

So if we add 0.005 mL of the original sample to 0.095 mL of sterile DI water, we're left with 0.1 mL of a 1:20 dilution.

Rounding up 0.005 mL to four decimal places, the answer thus is 0.0050 mL.