抄録
The passive hemagglutination test for serodiagnosis of syphilis with an antigen derived from pathogenic Treponema pallidum was investigated. The use of an improved reaction medium and the pretreatment of test serum with an antigen derived from a strain of non-pathogenic treponemes eliminated most of non-specific reactions. The method is highly specific and sensitive and is very simple to perform. The lyophilized antigen can be stored for a year without any appreciable change in the antigenicity. Thus, the method will be very useful for routine serodiagnosis of syphilis.