Figure 3From: Differential partitioning of Gαi1 with the cellular microtubules: a possible mechanism of development of Taxol resistance in human ovarian carcinoma cells PKA activity in the parental and taxol resistant cells before and after treatment with taxol. PKA activity was determined using the Pierce Colorimetric Assay Kit that utilizes a fluorescent-labeled Kempeptide (a PKA-specific peptide (LRRASLG) substrate). Untreated and taxol treated cells were homogenized in a Dounce homogenizer (10 strokes with a tight fitting pestle) in a buffer containing 25 mM Tris-HCl, pH 7.4, 0.5 mM EDTA, 0.5 mM EGTA, 10 mM DTT and protease inhibitor cocktail. The homogenate was centrifuged at 13,000 × g for 20 min and the PKA activity was measured (in triplicate) in the supernatant fraction. Values shown are mean ± SD of 3 separate experiments.Back to article page