tuberculin(redirected from Koch old tuberculin)
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a sterile liquid containing the growth products of, or specific substances extracted from, the tubercle bacillus; used in various forms in the diagnosis of tuberculosis (see tuberculin test).
Old tuberculin a sterile solution of a heat-concentrated filtrate of tubercle bacillus culture grown on a special medium, used for tuberculin tests.
PPD tuberculin (purified protein derivative tuberculin) a sterile solution of a purified protein fraction precipitated from a filtrate of tubercle bacillus culture grown on a special medium, used for tuberculin tests.
tuberculin test any of a large number of skin tests for tuberculosis using a variety of different types of tuberculin and methods of application. The most reliable procedure, now standard, is intradermal injection (the mantoux test) of PPD (purified protein derivative); a positive result consists of a palpable and visible area of erythema and induration greater than 10 mm in diameter developing around the site of injection 48 to 72 hours after the injection. Intermediate strength tuberculin (5 TU) is generally used to test adults; a positive result is virtually diagnostic of a previous or current infection with Mycobacterium tuberculosis. Persons with a negative test are retested with second strength tuberculin (250 TU); in this test a positive reaction is frequently due to atypical mycobacteria infection and is thus nonspecific; a negative result indicates either absence of tuberculosis or the presence of cutaneous anergy due to overwhelming tuberculosis infection or to an associated immunocompromised condition such as HIV infection, Hodgkin's disease, or sarcoidosis.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.
1. A glycerin-broth culture of Mycobacterium tuberculosis evaporated to 1/10 volume at 100°C and filtered; introduced by Robert Koch for the treatment of tuberculosis but now used chiefly for diagnostic tests; originally known as Koch old tuberculin (OT) or Koch original tuberculin
2. One or another of a relatively large number of extracts of Mycobacterium tuberculosis cultures, different from OT and now obsolete.
Farlex Partner Medical Dictionary © Farlex 2012
A sterile liquid containing proteins extracted from cultures of tubercle bacilli and used in tests for tuberculosis.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.
A glycerin-broth culture of Mycobacterium tuberculosis evaporated to 1/10 volume at 100°C and filtered; introduced by Robert Koch for the treatment of tuberculosis but now used chiefly for diagnostic tests; originally known as Koch old tuberculin (OT) or Koch original tuberculin.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012
A mixture of antigens obtained from the cultured bacteria that cause tuberculosis, Mycobacterium tuberculosis.
Mentioned in: Tuberculin Skin Test
Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.
A glycerin-broth culture of Mycobacterium tuberculosis evaporated to 110 volume at 100°C and filtered.
Medical Dictionary for the Dental Professions © Farlex 2012