Tuberculin

(tu-burf -ku-lin) [tuberculum, a tubercle]. A glycerol-extract of cultures of the bacillus of tuberculosis. It is a brownish, neutral liquid, soluble in water, and is used as a means of diagnosing tuberculosis, especially in the domestic animals; when injected into tuberculous individuals a reaction is produced which differs from that given by healthy individuals. It is also known as para to loid. 638