Pasteurized milk is allowed 20000cfuml How many colonies wou
Pasteurized milk is allowed 20,000cfu/ml. How many colonies would be present if 0.25ml of 10^-3 dilution was plated? show calculation
Solution
The number of colony-forming units (CFU) = [no of cells]/ [volume of dilution x volume of diluted sample added to the plate]
Now CFU per ml of dilution is ? colonies divided by 0.25 ml plated, = [? colony-forming units]/[0.25ml of dilution]
The number of colony-forming units (CFU) = [?colony-forming units] / [0.25ml x 10-3]
20,000 /10^3 = [?colony-forming units] / [0.25] = 5 colony-forming units/ml of original sample
Humans will not get any health hazard with this milk, of 5 colony-forming units/ml of original sample because raw milk has 40,000 to 50000 cfu/ml

