Replica Plating Technique for Studying Microbial Interactions in Soil

A replica plating method was developed to study ecology of microorganisms in soil. Precise placement of inocula and amendments at desired loci in sterile soil contained in petri plates were accomplished with a template. Subsequent growth and distribution of individual species, even when part of a mixed population, was measured by periodic transfer with an easily constructed replicator to agar plates of differing nutritional composition or containing selective inhibitors. The method is rapid and reproducible, and permits the study of many variables and interactions in a single soil plate; it can also be used with non-sterile soil and other suitable microbial habitats.