Isoenzyme patterns of cultured Trypanosoma cruzi: changes after prolonged subculture

1. The isoenzyme patterns of four soluble enzymes in seven stocks of T. cruzi were determined by electrophoresis. According to their patterns they could be classified into four sets. 2. The isoenzyme patterns of two stocks were influenced by the number of subcultures. 3. Five stocks from man are distinct from those derived from a silvatic reservoir. 4. Since the isoenzyme patterns of a stock isolated from a patient with acute disease were similar to those of a silvatic reservoir, its recent introduction into the domiciliary cycle is postulated.