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Multiple puncture tuberculin test (Heaf test), used to test for immunity to tuberculosis. A highly concentrated solution of tuberculin, a protein extract from cultures of tubercle bacilli, is applied to the skin. An instrument with six needles arranged in a circle is then used to puncture the skin. The type of reaction, read 3-10 days later, indicates the degree of immunity present. Individuals showing little or no reaction to the tuberculin have not suffered from or been in contact with the disease and have not developed any immunity to it. These can be inoculated with BCG (bacille Calmette-Guerin) vaccine, an attenuated strain of the bovine tubercle bacillus.
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