Latex agglutination kit used in a hospital pathology laboratory for grouping (identifying) haemolytic streptococci. Members of the streptococcus genus of bacteria are classified according to their degree of haemolytic activity (their destructive effect on red blood cells). S. pyogenes, for example, displays beta-haemolytic activity, indicated by complete lysis of red blood cells & the decolourisation of haemoglobin. Beta haemolytic streptococci are sub-divided into Lancefield groups A-H & K-V according to their antigenic structure.