Binding inhibition of anti-VpreB MoAbs to immobilized VpreB by the COOH-terminal V-preB peptide, using the BIAcore apparatus. Anti-VpreB MoAbs (20 μg/mL) were preincubated for 30 minutes in HBS buffer with serial concentrations of the COOH terminal VpreB peptide (0 to 100 μg/mL) and were injected at a flow rate of 5 μL/min in HBS buffer on a sensor chip surface containing 1,200 RU of recombinant human VpreB.