Detection of M Protein in Colonies of Streptococcal L Forms by Immunofluorescence.

Abstract

Summary M protein was detected in growing L-form colonies of Group A streptococci by an immunofluorescent technique which employs type-specific fluorescein-la-beled antibody. The type-specificity of the FA-staining reactions exhibited by the L forms was confirmed by parallel precipitin studies. These data suggest the feasibility of identifying the L-form colonies of Group A streptococci by detecting the M protein with the FA method.