Abstract: The presence of Group A Streptococcus in a biological specimen is determined from the presence of Streptococcus A antigen. A biological specimen is collected with an applicator having a plastic stick with a rayon swab. The swab is placed in an extraction reagent containing enzymes produced by the bacterium Streptomyces albus, wherein the enzymes release the antigen from the fiber. An aliquot of the extraction medium is mixed with an indicator reagent containing an antibody reactive with the antigen. The occurrence or non-occurrence of an antibody-antigen reaction is noted which indicates the presence or absence of Group A Streptococcus in the biological specimen.