Detection of single hinge cleaved trastuzumab and matrix metalloproteinases in breast cancer patient samples. (A) Same amounts of enriched IgGs from each sample were separated by SDS-PAGE under nonreducing/denaturing conditions. Arrow, single hinge cleaved trastuzumab (scIgG-T) as referenced to standard preparation in the right lane. (B) Detection of matrix metalloproteinase (MMP) expression in breast cancer patient tumor tissues and normal adjacent 2 cm tissue using a reverse protein array method (n = 4). *P < 0.05 and **P < 0.005. MW, molecular weight.