Fig. 2. Stabilization of microtubules with taxol prevents colchicine-induced development of polarity. For controls, neutrophils were either incubated for 60 minutes in medium (open bars) or preincubated for 30 minutes in medium followed by addition of 1 µM (hatched bars) or 20 µM taxol (closed bars) and a further incubation at 37°C. For cells stimulated with colchicine, cells were incubated with DMSO (open bars) or with 1 µM (hatched bars) or 20 µM taxol (closed bars) for 30 minutes at 37°C, followed by the addition of colchicine (10 µM) and a further incubation for 30 minutes. For cells stimulated with the chemotactic peptide fNLPNTL (CP), cells were preincubated for 30 minutes with DMSO (open bars) or with 1 µM (hatched bars) or 20 µM taxol (closed bars) at 37°C followed by addition of 1 nM fNLPNTL and a further incubation for 30 minutes. Cells were fixed with glutaraldehyde and the percentage of polarized cells assessed using Nomarski optics for 100 cells per sample. Mean±s.e.m. of four experiments.