“…Electrophoresis has been extensively used for speciating these microorganisms (1, 3, 6, 7, 9-11, 14-17, 19, 20, 22, 24, 25). The first such attempt, with a starch gel system, revealed a considerable number of patterns in the soluble fractions of mycoplasma proteins (10). The use of polyacrylamide, as a disc gel (1, 3, 6, 7, 9, 11, 14-17, 19, 20, 22), or direct comparison, as a flat gel (24,25), requires solubilization of the cells, either in a phenolacetic acid-water mixture (14) or in sodium dodecyl sulfate (6).…”