Studies on the Tuberculin Reaction Part 1. on the Changes of Tuberculin Antigen due to Digestive and chemical and Chemical Degeneration

By making protein degenerant and protein digestive enzyme act on old tuberculin the author performed the tuberculin reaction, and obtained the following results. 1. In loading a strong potassium iodide solution to old tuberculin the tuberculin reaction grows weaker along with an increase in the concentration of potassium iodide. This suggests that free tyrodine radical in the old tuberculin protein is involved in the tuberculin reaction. 2. In loading sodium nitrite to old tuberculin the tuberculin reaction likewise grows weaker with increase in the concentration of sodium nitrite 3. In the addition of formalin to old tuberculin the tuberculin raction is weakened along with increaes in the concentration of formalin solution. 4. When crystalline trypsine is made to act on old tuberculin, the tuberculin reaction is weakened along with lapse in the digestion time. 5. When pepsin is made to act on old tuberculin, the tuberculin reaction is likewise weakened along with lapse in the digestion time. 6. From these results it is deduced that the tuberculin reastion is mainly controlled by tuberculin protein.