Specific skin-reactive protein from culture filtrate of Mycobacterium bovis BCG.

A highly purified protein, named MPB70, was isolated from the culture filtrate of Mycobacterium bovis BCG. This protein accounted for more than 10% of the proteins secreted into the culture medium. MPB70 was purified by precipitation with ammonium sulfate, followed by treatment with diethylaminoethyl ion exchanger, with or without 3 M urea, and by gel filtration.

Tuberculin peptide from culture filtrate of Mycobacterium tuberculosis.

A highly purified tuberculin peptide, named TPH71U, was isolated from the heated culture filtrate of Mycobacterium tuberculosis strain H37Rv. This peptide was prepared by precipitation with ammonium sulfate and by treatment with diethylaminoethyl-Sephadex, Sephadex G-75, and preparative gel electrophoresis in the presence of a high concentration of urea. The presence of urea remarkably increased the sensitivity of the gel analysis and the efficiency of the preparation procedure.

Various antigenic reactivities in delayed hypersensitivity among crystalline proteins from Mycobacterium phlei.

Comparisons were made of the delayed-type skin reactivity of 6 crystalline proteins purified from the cell extract of Mycobacterium phlei in guinea pigs sensitized with whole cells of the heat-killed bacillus. These highly purified proteins elicited varying degrees of cutaneous reaction. The most active protein had almost the same reactivity as purified protein derivative prepared from the culture filtrate of Mycobacterium phlei.