Source : Webster's Revised Unabridged Dictionary (1913)

Tuberculin \Tu*ber"cu*lin\, n. [See {Tubercle}.]
   A fluid containing the products formed by the growth of the
   tubercle bacillus in a suitable culture medium.

Source : WordNet®

tuberculin
     n : a sterile liquid containing a purified protein derivative of
         the tuberculosis bacterium; used in the diagnosis of
         tuberculosis