Kit Components R0400-55A: PAK-1 PBD, agarose. 1x300ug of PAK-1 PBD bound to 150ul of glutathione agarose beads, provided as a 50% slurry in 20mM PBS, pH 7.4, containing 50% glycerol for a final volume of 300ul. R0400-55B: Rac1 Mab: 1x250ug in 250ul of 0.1M Tris-glycine, pH 7.4, 0.15M NaCl, containing 0.05% sodium azide. Protein G purified mouse IgG2b. R0400-55C: Mg2+ Lysis/Wash Buffer, 5X, 2x18ml Supplied as a liquid in125mM HEPES, pH 7.5, 750mM NaCl, 5% Igepal CA-630, 50mM MgCl2, 5mM EDTA and 10% glycerol. R0400-55D: GTPgS (100X) 1x50ul of 10mM GTPgS, 100X stock, in sterile, distilled water. Non-hydrolyzable analog of GTP. Sufficient to label 5ml of cell lysates. R0400-55E: GDP (100X) 1x50ul of 100mM GDP, 100X stock, in sterile, distilled water. GDP (Guanosine 5- Diphosphate) for in vitro labeling of G-proteins in the inactive form. Sufficient to label 5ml of cell lysates. Quality Control Testing: The kit precipitated Rac1- GTP from 3T3 cell lysates that had been loaded with GTPgS. A previous lot precipitated Rac1-GTP from HL-60 lysates. The precipitated Rac1-GTP was detected by immunoblot analysis using anti-Rac1 (1ug/ml). Three to four additional bands at and above 30kD may be detected in HL-60 lysates loaded with GTPgS.