Differential action of staphylococcal alpha-toxin on young and old erythrocytes.

Band 3 of rabbit erythrocytes is a binding site for staphylococcal alpha-toxin. Young erythrocytes have a functionally intact band 3 of 100 kD that is hydrolysed as the cells age into a 35-kD fragment. Consequently, aging of erythrocytes renders them more resistant to the action of the toxin. Thus the age of a blood sample will reduce the sensitivity of the hemolytic assay and contribute to the variation of this assay.