Differentiation of several isolates of Peptococcus magnus by counterimmunoelectrophoresis.

Uniform sonicated suspensions of three clinical isolates of Peptococcus magnus that were morphologically, chromatographically, and biochemically identical were used to produce hyperimmune antisera in rabbits. Similar hyperimmune serum was prepared to a single strain of Peptostreptococcus anaerobius. When these antisera and antigens were tested by counterimmunoelectrophoresis, the three isolates of Peptococcus magnus were immunologically distinct. None of the antisera to Peptococcus magnus formed precipitin lines with Peptostreptococcus anaerobius.