Ganetespib (STA-9090) is a synthetic small-molecule inhibitor of heat shock protein 90 (Hsp90) with potential antineoplastic activity.

Exponentially growing cells are processed in lysis buffer (20 mM HEPES, pH 7.4, 1 mM EDTA, 5 mM MgCl2, 100 mM KCl) and incubated with increasing concentrations of 17-AAG or ganetespib for 30 min at 4°C, and incubated with biotin-GM linked to Dynabeads MyOne Streptavidin T1 magnetic beads for 1 h at 4°C. Beads are washed three times in lysis buffer and heated for 5 min at 95°C in SDS-PAGE sample buffer. Samples are resolved on 4-12% Bis-Tris gradient gel and Western blots are performed using an anti-HSP90 antibody.

A total of 1.5 × 103 OSA cells are seeded in 96-well plates in 10% serum-containing complete medium and incubated overnight to determine the 50% inhibitory concentrations. Plates are, harvested at day 5 following 0.001, 0.005, 0.01, 0.05, 0.1, 0.5 and 1 μM Ganetespib, treatment and analyzed. Fluorescence measurements are made using a plate reader with excitation at 485 nm and emission detection at 530 nm. Relative cell number is calculated as a percentage of the control wells: absorbance of sample/absorbance of DMSO treated cells × 100.(Only for Reference)