Fig. 1

Removal of immunoglobulin binding proteins from S. aureus cell wall extracts by affinity chromatography. a Intravenous immune globulin (IVIG) was digested with recombinant IdeS and Fc fragments were purified by size exclusion chromatography (SEC) prior to immobilisation onto cyanogen bromide activated agarose. b 5 µl aliquots of S. aureus CWE from three clinical isolates were spotted onto a Hybond-LFP membrane before and after protein A removal and probed with 5 µg/ml of SEC purified Fc fragments. c 5 µg of protein A-depleted CWE from five S. aureus isolates (CC8) were visualised by immunoblotting using 5 µg/ml of IdeS-cleaved IVIG (left) or IVIG (right) as a primary antibody. For b, c, bound primary antibodies were detected by exposure to chemiluminescent film using a 1: 80,000 dilution of Fc specific goat anti-human IgG (HRP-conjugated) and ECL prime