Preparation of 14C-labeled Tuberculin Purified Protein Derivative

摘要

¹⁴C-labeled tuberculin purified protein derivative (¹⁴C-tuberculin PPD) has been prepared from culture filtrates of Mycobacterium tuberculosis var. hominis grown in a culture medium containing uniformly labeled ¹⁴C-amino acids. With a mixture of ¹⁴C-amino acids (an acid hydrolysate of ¹⁴C-Chlorella protein) in the medium, the recoveries of ¹⁴C in the final product were higher than with ¹⁴C-labeled-l-glutamic acid. ¹⁴C-tuberculin PPD was separated into tuberculoprotein and nucleic acid by paper electrophoresis. The specific radioactivity of tuberculoprotein was substantially greater than that of the nucleic acid. ¹⁴C-tuberculin PPD is advocated as a means to measure the adsorption of tuberculin to glass or other surfaces. It could also prove useful as a means to study the structure and mode of action of tuberculin.