Some factors influencing the tuberculin tine test

Some physical factors influencing the performance of the tuberculin Tine Test have been investigated. Conditions under which tuberculin is removed from the tines were examined, by direct observation of elution with water, and by insertion into a number of materials, including human and animal skin. Uptake of tuberculin on to tines was also studied and quantitative estimates were obtained by dipping the tines in tuberculin mixed with 32P; it was found that the amount of tuberculin adhering to the tines was approximately doubled by applying a second coat after the first had dried. Tines coated with this mixture were applied to human skin from a cadaver, and after removal it was noted that approximately half the tuberculin orginally coating the tines had been deposited in the skin; the quantity inserted by doubly-coated tines was approximately double that deposited by singly-coated ones.