“…The reliability of this reaction to distinguish allergic from non-allergic sera has recently been questioned [18][19][20] due to high degranulating activity of control sera (in the absence of antigen) and lack of re producibility. In addition, there was no apparent relationship between the basophil degranulating and reaginic activities of Scphadex G-200 or DEAE-Sephadex fractions of allergic human sera [21]. S c h w a r t z et al [22] found that rat peritoneal mast cells could be utilized to dis tinguish sera from penicillin or insulin sensitive patients from those of non-allergic individuals.…”