"DROP PLATE" METHOD OF COUNTING VIABLE BACTERIA

Abstract

This paper is a critical review of the "drop plate" method of determining the number of viable bacteria in fluids, together with a description of an experimental comparison of the "drop plate" with the more usual "pour plate" procedure. It is shown that counts on pure cultures of bacteria made by the "drop plate" method are some 7% higher than those made on the same cultures by the "pour plate" method. It is also shown that the standard error of a series of counts made by the "drop plate" procedure is slightly less than for those made by the "pour plate" method.