Calculate the colony forming units/ml of original sample if you counted 250 colonies on plate with a dilution factor of 10^5. Give your answer in scientific notation.

The correct answer is = 2.5× 10^7.

Explanation:

Colony Forming Units/ml (CFU/ml) in the original sample can be calculated by the countable plate is multiplied by 1/FDF.

Given:

colonies counted on the plate = 250

Forming dilution factor = 10^5

solution:

CFU/ml = 250  x 1/1/100000

= 250 CFU x 100000

= 250,00,000 CFU/ml

= 2.5× 10^7

50% lit on the left side

answer; both surfaces of the membrane are nonpermeable