Fractional precipitation is a simple, efficient method for pre-purifying paclitaxel extracted from plant cell cultures. However, the fractional precipitation process has been inherently problematic due to the lengthy precipitation time (similar to 3 days) that is required. An improved fractional precipitation process could significantly reduce the precipitation time by increasing the purity of crude extract and the surface area available for precipitation. Glass beads (7 mm) were used to increase the surface area, and the optimal Surface area per working volume (i.e. volume of reaction solution) (S/V) for achieving the highest purity and yield of paclitaxel possible was found to be 0.428 mm(-1). The content of paclitaxel dissolved in methanol that can be processed during fractional precipitation was evaluated, and it was established that up to 0.9% (w/v) pure paclitaxel content could be processed. This improved pre-purification process serves to minimize solvent usage and the size and complexity of the high performance liquid chromatography operation required for paclitaxel purification. (C) 2009 Elsevier Ltd. All rights reserved.