5(6)-ROX [5-(and-6)-Carboxy-X-

Labeling Tubulin and Quantifying Labeling Stoichiometry

) 5 (and-6) carboxy-X-rhodamine succinimidyl ester ( Molecular Probes C-1309) Texas Red-X succinimidyl ester, mixed isomers ( Molecular Probes T-6134) Cy3-OSu monofunctional reactive fluorophore ( Amersham PA13100) Cy5-OSu monofunctional reactive

Preparation of Segmented and Polarity Marked Microtubules

made as a 5X stock and stored at 4¡C) 100 mM GTP 100 mM GMPCPP Taxol : 10 mM stock; 200 µM, 20 µM and 2 µM dilution all in anhydrous DMSO; sold under tradename "Paclitaxel" by Sigma Bright GMPCPP Seed Mix (2 mg/ml; 1 part rhodamine tubulin

Preparation of Segmented and Polarity Marked Microtubules

, 1 mM MgCl2 , 1 mM EGTA, pH 6.8 with KOH (generally made as a 5X stock and stored at 4¡C) 100 mM GTP 100 mM GMPCPP Taxol : 10 mM stock; 200 µM, 20 µM and 2 µM dilution all in anhydrous DMSO; sold under tradename "Paclitaxel