Mechanisms of Purifying Amoebae by Migration on Agar Surfaces

SYNOPSIS. Purification by migration on solid agar plates was studied with a small soil amoeba, Acanthamoeba sp., and a large fresh-water amoeba, Amoeba proteus. Purification seems accomplished largely by two mechanisms: egestion and attrition of contaminating organisms. Digestion may also play a role but probably is less important. The migration method is applicable to motile forms of the two amoebae which differ greatly in volume and motility. Therefore the method may be of potential value in purifying many species. Modifications which should extend the usefulness of the method are considered.