The standardisation of tuberculin and the precipitin test / by C.C. Okell [and others].

Date:
1926?]
Catalogue details

Licence: In copyright

Credit: The standardisation of tuberculin and the precipitin test / by C.C. Okell [and others]. Source: Wellcome Collection.

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    Reprinted from The Lancet, Feb. 21th, 1920, p. 433 R J 7 i'-S ryr THE STANDARDISATION OP TUBERCULIN AND THE PRECIPITIN TEST. By C. C. OKELL, M.C., M.R.C.P. Bond., H. J. PARISH, M.D., M.R.C.P. Edin., and R. A. O’BRIEN, C.B.E., M.D. Melb., WELLCOME PHYSIOLOGICAL RESEARCH LABORATORIES ; G. DREYER, C.B.E., M.A., M.D., P.R.S., and R. L. VOLLUM, D.Phil. Oxf., DEPARTMENT OF PATHOLOGY, UNIVERSITY OF OXFORD ; S. LYEE CUMMINS, C.B., C.M.G., M.D. N.U.I., WELSH NATIONAL SCHOOL OF MEDICINE AND KING EDWARD VII. WELSH NATIONAL MEMORIAL ASSOCIATION, CARDIFF ; AND J. B. BUXTON, M.A., F.R.C.Y.S., INSTITUTE OF ANIMAL PATHOLOGY^, UNIVERSITY OF CAMBRIDGE. The testing of tuberculin by methods based on the official test in use at Frankfort has been carried on in England for many years. Eagleton and Baxter (1923) used the official Frankfort method, m which varying' doses of tuberculin are injected subcu taneously into different tuberculous guinea-pigs until the lethal dose is found ; they added the von Pirquet and intracutaneous tests and thereby considerably improved the method. With the methods at present available the degree of accuracy attainable is of a different order from that ordinarily obtained in the testing of diphtheria and tetanus toxins and their antitoxic sera, which lend themselves to accurate titration, but the test nevertheless distinguishes at least a “satisfactory’ from a “ useless ” tuberculin. It is probable that an experienced worker can differentiate, on a shoit range of tests, between three tuberculins of values 100 per cent.—i.e., equal to standard tuberculin 60 and 30 per cent. ; on a long range of tests smaller differences probably can be detected. The standard tuberculins used m the work in England have been based upon those of Frankfort since the receipt of the first standard from Ehrlic several years before the war, and many different batches of tuberculous guinea-pigs have been used with fairly consistent results. . Dreyer and Vollum (1924) described a precipitin test and found that considerable discrepancies might exist between the results obtained by the guinea-pig method and the precipitin test. Table I. summarises these results.