Western immunoblotting of blister and synovial fluid. (A) Western immunoblotting of CD11a and CD18 subunits in 16-hour blister fluid and a synovial effusion from a patient with inflammatory arthritis, using mAbs 38 and 2E7, respectively. Lysates from purified neutrophils (PMN) are shown as a reference standard for full-length CD11a and CD18 chains. (B-C) Comparison of CD18 blotting using mAb 2E7 and anti–C-terminal antibody. Molecular weight size standards are shown on the left. Arrows on the right indicate the position of full-length (180 kDa and 90 kDa) and truncated (110 kDa and 86 kDa) CD11a and CD18 chains, respectively.