Complement-fixation with small volumes of reagents; application to a Treponema pallidum complement-fixation test for syphilis (tpcf 50).

Abstract

The use of complement-fixation as a research or diagnostic tool depends, among other factors, on the availability of antigens. When antigen is scarce or expensive, the full potential of the complement-fixation test may not be realized. The application of the Treponema pallidum complement-fixation (TPCF) test' has in part been limited by the cost of the antigen per test. To overcome this limitation, the use of smaller amounts of antigen in a complement-fixation test using small volumes was considered. In the interests of practicability and reproducibility, it seemed desirable to use a technic that would require only conventional glassware and equipment. For these reasons the plate method as used in viral diseases and the micro method proposed by Eckert and his associates were not investigated. The author's purpose in this paper is to describe a complement-fixation test that uses a final volume of 0.125 ml. and its application to a Treponema pallidum complement-fixation test for syphilis designated as tpcf 50. Using a period of fixation in a water-bath, the test is completed the same day. I t has been possible to achieve an approximately 8-fold increase in the number of doses of antigen over that obtained by the use of the original TPCF test. The results obtained with this new procedure in comparison with other serologic tests are presented and discussed.