Purification and Biochemical Properties of Rac1,2,3 and the Splice Varia nt Rac1b; Biochemical Analyses of the Wrch Atypical Rho Family GTPases; Purification of P-Rex1 from neutrophils and nucleotide exchange assay; In vitro guanine nucleotide exchange activity of DHR-2/DOCKER/ CZH2 do mains; Biochemical characterization of the Cool (Coned-out-of-Library)/P ix (Pak-interactive exchange factor) proteins; GEF and glucosylation ass ays on liposome bound Rac; Phosphorylation of RhoGDI by p21-activated ki nase 1; Purification of ARAP3 and characterization of GAP activities; Re gulation of RhoGAP specificity by phospholipids and prenylation; Purific ation and activity of the Rho ADP-ribosylating binary C2/C3 toxin; Puri fication of Tat-C3 exoenzymes; Imaging and photobleach correction of Mer oCBD, sensor of endogenous Cdc42 activation ; Cdc42 and PI(4,5)P2-induc ed actin assembly in Xenopus egg extracts; In Vitro Reconstitution of Cd c42-Mediated Actin Assembly Using Purified Components; Biochemical Analy sis of Mammalian Formin Effects on Actin Dynamics; Formin proteins: puri fication and measurement of effects on actin assembly; Purification and