tuberculin reaction

tuberculin reaction,

hardening or blistering as a delayed reaction at the site of a tuberculin test, a positive result that indicates previous exposure to either the vaccine or the disease.

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tuberculin

a sterile liquid containing the growth products of, or specific substances extracted from the tubercule bacillus; used in various forms in the diagnosis of tuberculosis.

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heat concentrated synthetic medium (HCSM) tuberculin

similar to old tuberculin, but grown on synthetic medium.

new tuberculin

a suspension of the fragments of tubercle bacilli, freed from all soluble materials and with glycerine added.

old tuberculin

a sterile solution of concentrated, soluble products of the growth of the tubercle bacillus, adjusted to standard potency by addition of glycerin and isotonic sodium chloride solution, final glycerin content being about 50%.

purified protein derivative (PPD) of tuberculin

a form of tuberculin used in the testing of animals for tuberculosis; abbreviated PPD. It is a soluble protein fraction prepared from a synthetic medium on which the Mycobacterium bovis has been cultured. It has the advantage of reducing the number and severity of the reactions caused by nonspecific sensitizing materials in the culture medium in old tuberculin.

tuberculin reaction

the prototype delayed or type IV hypersensitivity; typified by swelling and redness at the site of inoculation of tuberculin.

tuberculin tests

a number of tests for tuberculosis, based on the use of tuberculin as a test agent, are used in animals. A short thermal test using a large volume of tuberculin injected subcutaneously is used in special circumstances. Most of the tests use an intradermal injection and a local swelling as a positive reaction.