[Group diagnosis of streptococci. II. - Comparative study of precipitation technics in liquid and gelified media].

The identification of the antigenic group of streptococci is based on an interphasic precipitation reaction in liquid medium (Lancefield). The authors propose to adapt to the identification of streptococcal groups, the techniques of precipitation in gel medium, They compare in 220 strains the techniques of immunodiffusion (Ouchterlony) and immunoelectro-osmophoresis, giving their preference to the latter which is safe, specific, economic and rapid.