Rapid fluorescent-antibody stain technique with group A streptococci.

A rapid fluorescent-antibody stain technique used with young broth cultures of trypsinized group A streptococci is described. Results from 1,214 trypsinized cultures of group A streptococci employing the rapid stain method were equivalent, both in specificity and sensitivity, when compared to results obtained from identical non-trypsinized cultures stained with the longer standard technique of Cherry, Goldman, and Carski. Moreover, the rapid method requires less than 2 min to complete.