title: Acid-precipitated M protein compared with a column-eluted M protein preparation from type 12, group A Streptococci.
abstract: An M protein preparation of group A streptococci, precipitated with 0.03 m sodium acetate buffer (pH 4.0) was compared with a column-eluted M protein preparation. Absorption spectra and methyl pentose content were similar in both preparations. Acrylamide gel electrophoresis patterns were different. Gel diffusion demonstrated two lines of fusion in the preparations. More antigens could be demonstrated in both preparations by using immunoelectrophoresis. Neither the pH 4 precipitate nor the column-eluted preparation appeared to be a pure M protein preparation.
mesh_terms: D000941:Antigens / Q000032:analysis; D001426:Bacterial Proteins / Q000032:analysis*; D002473:Cell Wall / Q000032:analysis; D011232:Chemical Precipitation; D004586:Electrophoresis; D005779:Immunodiffusion; D007122:Immunoelectrophoresis; D013053:Spectrophotometry; D013297:Streptococcus pyogenes / Q000032:analysis*
chemical_list: D000941:Antigens; D001426:Bacterial Proteins