Quantification of mitotic cells via immunocytochemistry. U2OS cells were treated with DMSO (negative control), F5, nocodazole (noc, positive control) or colchicine (col, positive control) for 24 h before staining of cells for phospho-histone H3 and DNA. Cells in mitosis were quantified as the percentage of phospho-histone H3-positive cells. Data are mean values s.d. of three independent replicates ( n = 3). Statistical analyses were performed relative to the DMSO control by employing unpaired two-tailed t-tests (**** P < 0.0001). The P values relative to cells treated with DMSO are <0.0001 for F5 (10 M)-treated, <0.0001 for F5 (30 M)-treated, <0.0001 for noc-treated and <0.0001 for col-treated cells.
