In 96-well plates, non-biotinylated test peptide at a concentration of 100 μM competes for binding to purified Class II molecules (50 nM). Blue bar is average across alleles. Dots represent percent inhibition of binding to HLA alleles: DRB1*0101, DRB1*0301, DRB1*0401, DRB1*0701 and DRB1*1501. The amino acid modifications were made to prevent binding across all HLA DR alleles; however, the predicted changes were not always universal and therefore some peptides could be expected to demonstrate residual binding to selected MHC.