Explain why it is better to use ‘density of a population’ rather than absolute number

Answer 1

Hi Amy,

Finding the density of bacterial sample can easily be done by serial dilution of the sample until about 300 colonies form when a quantity is plated on agar plates. Counting 300 colonies and then multiplying by the dilution will allow us estimate the microbial density of a sample. In contrast, counting every cell to get an absolute number is going to take a lot of plates since a typical turbid liquid culture contains 10^8 cells.

Hope this helps!

Andrew