New Design for an Automated Bacterial Colony Counter

Abstract

The discovery that translucent bacterial colonies growing on the surface of an agar medium take the form of spherical lenses allows the design of a new generation of automated bacterial colony counters. The lens properties of these colonies are explored in detail and a parallel scanning technique, ``nearest neighbor inhibition,'' which allows an electronic system to produce only one count for each colony detected, is described. A complete colony counting instrument is presented and its possible sources of error are discussed.