Use of the Streptosec test for grouping beta-haemolytic streptococci.

The Streptosec test, which embodies the coagglutination principle for grouping beta-haemolytic streptococci, was used against 72 streptococci previously grouped by precipitin methods. Only two of the 72 strains failed to react. The test is easy to manipulate, represents a considerable saving in time and effort, and produces results with an acceptable degree of accuracy.