Effect of EACA on the binding of anti-Pg RIBS mAbs to surface-bound Glu-Pg. Binding of RIBS mAbs or MOPC21 isotype control(180nM) to immobilized Glu-Pg was determined in the presence of either buffer (□), soluble Glu-Pg (1μM) in the absence (■) or presence () of EACA (0.2M), or in the presence of EACA alone (▨). Additional controls show absorbance in the absence of Ab (No Antibody). **P < .001 for soluble Glu-Pg in the presence of EACA compared with soluble Glu-Pg in the absence of EACA.