Detection of "neutral" type 7F and type 14 pneumococcal capsular polysaccharides by immunoelectrophoresis

Type 7F and type 14 pneumococcal capsular polysaccharides, neutral at pH 8.6, were studied by immunoelectrophoresis at pH 5. Three techniques were used: rocket, countercurrent, and reversed immunoelectrophoresis. Our results show that these two capsular polysaccharides types can be detected at pH 5 with high sensitivity.