An evaluation of the polyacrylamide gel electrophoresis fractionation method for the production of Mycobacterium tuberculosis skin test preparations I. Production, physiochemical characterization and serological analyses

Abstract As a part of a cooperative inter-laboratory WHO supported project raw tuberculins were produced and purified protein derivative (PPD, 18·7 g protein) was prepared. Employing a multistage preparative polyacrylamide gel electrophoresis (PAGE) method the PPD was separated into four fractions corresponding to 15, 7, 4·75 and 3·5% gel concentrations. The PAGE procedure resulted in three lots of material—each representing 11 electrophoretic runs. Immunodiffusion analyses showed that the largest number of precipitinogens was found in the 15% fractions and that some precipitinogens cross-reacted with preparations of Mycobacterium bovis BCG, M. intracellulare, M. kansasii, M, smegmatis and M. vaccae .