In 1925 Frei1 reported the use of an antigen made with pus obtained from an unruptured bubo of a patient suffering from lymphogranuloma venereum. Ever since, this test has been recognized as a valuable aid in diagnosis. However, because of difficulty experienced in obtaining sufficient material for its preparation, other sources have been investigated. The artificially infected brain of various animals was found satisfactory, and the susceptibility of mice to the virus, shown by Levaditi, Ravaut and Schoen2 in 1932, led to the subsequent utilization of mice in the preparation of an antigen.
The mouse brain antigen, with a suspension of normal mouse brain used as a control, has been studied by many clinicians and found satisfactory when the reactions are properly read, although Binkley and Love3 advocated its abandonment, considering the results too difficult to interpret. Reider and Cañizares,4 at Bellevue Hospital, after a study