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You are given a culture of bacterial cells of unknown concentration. You are asked to determine...

You are given a culture of bacterial cells of unknown concentration. You are asked to determine the concentration (cells/mL). You make three serial dilutions of 100-fold and a final 10-fold dilution of the sample. After plating 1 mL of this culture dilution on a growth plate, you generate 42 bacterial colonies (each colony represents a single bacterial cell that was on the plate). What was the concentration of the original bacterial cell culture?

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Answer #1

The concentration of the original given bacterial cell culture was 4.2X108 cells/mL.

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