抄録
Since Koch's discovery of tuberculin, the active principle of tuberculin has long been the subject of many researchers, and a significant advance was made in the study of the nature of tuberculin' when Seibert and Long and their associates (1, 2, 3, 4) wsucceeded in the isolation of the tuberculin active principle apparently in pure form, and as a result of which, as is well known, it has now become possible to compare accurately the tuberculin sensitiveness of human beings in the field testing.
Quite recently, working preliminarily with Maschmann's purified tuberculin (5, 6), and, following this, with Sauton's synthetic-medium Old Tuberculin, Ito and Koshimura of our laboratory have succeeded in establishing a simple procedure for preparing ο-aminophenol azo-tuberculin derivative quite equivalent in skin-reacting potency to the P. P. D. (purified tuberculin derivative) of Seibert. The new process is especially significant, in that it provides us with ο-aminophenol azo-tuberculin preparations possessed of practically uniform skin-reacting potency in good quantities.
Although much work has been done in the research concerning the effect of chemical modification on the immunological reactivity of protein antigens (7, 8), there has, insofar ns the writer is aware, been practically no work done towards the isolation of the active principle of tuberculin in the form of its azo-derivative.
In this paper I have tried to review the principal results of the research work which has been done in our Institute for these past two years.
