Starch–Agar-Gel Electrophoresis of Tuberculoproteins from Heated Culture Filtrates

Abstract

IN order to improve the specificity of a bovine tuberculin purified protein derivative, precipitated with trichloracetic acid from heated culture filtrates¹, we decided to investigate its protein composition², and in this connexion we experimented with zone electrophoresis on paper-strips. Now this procedure has hitherto not been very successful^3–5, and in spite of our own numerous experiments with various procedures and methods we did not obtain anything other than unusable pictures of ‘comets’ or streaks. (This is in contrast with the more satisfying results obtained by others with non-heated tuberculins^4,5.) Smithies introduced starch gel electrophoresis which seems to be of great value in determining the ultrastructure of serum-protein patterns^6,7, the composition of toxins⁸ and of cerebrospinal fluid⁹. Sorkin et al. ¹⁰ made preparative separations of some tuberculoprotein preparations from unheated culture filtrates by electrophoresis in starch gels, followed by transfer into glass. Our own investigations on this starch-gel electrophoresis led to the following method.