Microbial limit test (MLT) is useful test to count the number of microorganisms per gram and pathogens. Microbial limit test has two parts a) Total microbial count b) Pathogens.

Total Microbial Count test is done to count the number of bacteria and fungus in pharmaceutical products.

Pathogens like E.coli, Salmonella, Pseudomonas, Staphylococcus and Clostridium are tested using different selective medium.