The reagin screen test: a new reagin card test for syphilis.

A new card test for syphilis, the reagin screen test (RST), employs a stabilized cardiolipin--cholesterol-lecithin antigen stained with Sudan black. The sensitivity and specificity of the RST are essentially the same as those of the Venereal Disease Research Laboratory (VDRL) test. The RST is quick and is easy to perform since the specimen of serum does not have to be inactivated by heat or transferred from the tube into which blood was drawn. The results of the test are read macroscopically on a card. The RST antigen is ready to use at all times, and it is stable for at least two years.