Abstract
A capillary procedure for quantitatively determining M protein is described. Capillaries were filled with measured amounts of serum and streptococcal extract. The capillaries were incubated, and then centrifuged to pack the precipitates. The relative sizes of the precipates were compared by a determination of the weights of their paper images (obtained by reflection from a microscope). Meaningful dilution curves were determined by this method. Variations of pH from 6 to 8 had little effect on the M protein precipitin test, and the test was not seriously affected by variations of the NaCl concentration from 0.85 to 4.67%. The addition of divalent ions (Ca++ and Mg++) did not influence the results. This test can be used to make quantitative comparisons of M protein preparations and to titrate type-specific antisera.
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Selected References
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- BROCK T. D. EFFECT OF ANTIBIOTICS AND INHIBITORS ON M PROTEIN SYNTHESIS. J Bacteriol. 1963 Mar;85:527–531. doi: 10.1128/jb.85.3.527-531.1963. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Becker C. G. Enhancing effect of type specific antistreptococcal antibodies on emergence of streptococci rich in M-protein. Proc Soc Exp Biol Med. 1967 Jan;124(1):331–335. doi: 10.3181/00379727-124-31736. [DOI] [PubMed] [Google Scholar]
- Fox E. N., Wittner M. K., Dorfman A. Antigenicity of the M proteins of group A hemolytic streptococci. 3. Antibody responses and cutaneous hypersensitivity in humans. J Exp Med. 1966 Dec 1;124(6):1135–1151. doi: 10.1084/jem.124.6.1135. [DOI] [PMC free article] [PubMed] [Google Scholar]
- MOODY M. D., PADULA J., LIZANA D., HALL C. T. EPIDEMIOLOGIC CHARACTERIZATION OF GROUP A STREPTOCOCCI BY T-AGGLUTINATION AND M-PRECIPITATION TESTS IN THE PUBLIC HEALTH LABORATORY. Health Lab Sci. 1965 Jul;2:149–162. [PubMed] [Google Scholar]