Effect of room temperature on serologic tests for syphilis.

The effects of temperature on the results obtained in the older serological tests for syphilis employing lipoidal antigens is well known. In fact, the differences in test results obtained when certain tests were performed at different temperatures served not only as the basis for attempted differentiation of syphilitic from so-called biologic false positive reactions (Kahn, 1940), but also for determining the relative specificity of different lots of lipoidal antigens (Kline and Suessenguth, 1946). Other workers have shown that test sensitivity is affected not only by the temperature at which the antigen-saline emulsions are prepared (Cannefax and others, 1953) but also by the temperature of the glassware and reagents (Fugazzotto, 1953). Exposure of blood or serum samples to temperatures above those employed for refrigeration increases the rate of haemolysis on the one hand and depresses the serological titre on the other, in proportion to the duration of exposure and the elevation of temperature. Most of the widely used serological tests for syphilis, with the exception of those performed at 4 to 60 C. or 370 C., are carried out at so-called " room temperature ", but this term becomes meaningless when the wide seasonal variations in laboratory temperatures which occur nationally and internationally are considered. In order to show the effect of these temperature