Clone it 57

Mtb samples were pelleted and resuspended in buffer containing 10 mM sodium phosphate pH 8.0, 150 mM NaCl, 2 mM EDTA, 1 mM PMSF, 0.1% NP-40, and a 1× protease inhibitor cocktail (Roche), then lysed by bead beating, and filtered two times through a 0.22-µm Spin-X column (Costar) to remove unlysed Mtb. SDS-polyacrylamide gel electrophoresis was performed and samples were transferred to a nitrocellulose membrane, after which KatG was detected using a mouse monoclonal α-KatG antibody used at 1:500 dilution (clone IT-57; BEI Resources). Either CarD or RpoB served as a loading control, using a mouse monoclonal α-CarD antibody at 1:2,000 dilution (clone 10F05; Memorial Sloan-Kettering Cancer Center) or a mouse monoclonal α-RpoB antibody at 1:1000 dilution (clone 8RB13; Neoclone). The membrane was probed with a goat anti-mouse antibody conjugated to horseradish peroxidase and bands were visualized using the Western Lighting Plus-ECL reagent (PerkinElmer). When performing the KatG expression analysis in response to C10 treatment, the amount of protein in each sample was measured by BCA (Pierce) and the amount of protein loaded in each lane was normalized to 67 ng to facilitate comparisons between samples.