Saline Agar is recommended or alpha-toxin detection in Clostridium perfringens. Saline Agar Base with blood is used to measure the haemolytic activity of alpha toxin. Red blood cells are added in the medium to examine haemolytic reactions, which indirectly helps in detection of alpha toxin. To determine whether the haemolysis caused by the extract is due to alpha toxin, a portion of the 1:2 dilution of the extract is mixed with C. perfringens alpha toxin and with C. perfringens type A diagnostic antiserum containing alpha toxin and placed in the two center wells. The plates are incubated for 24 hours at 35°C and examined for haemolytic zones surrounding the wells. A 1 mm zone of haemolysis is considered as significant.
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