Effect of CD11 and CD18-blocking antibodies on the formation of clumps. A Semi-quantitative PCRs were performed to detect the expression of the ICAM-1 transcript. GAPDH is used as a DNA amount control. B A375, 1205LU and SLM8 cell lines were treated with 2 μg/ml of CD11a or CD18-blocking antibodies as indicated. Melanoma cells were labeled with DiO then fixed and labeled with DAPI prior to their observation under an epifluorescence microscope using a magnification of x10. Data were obtained from 3 independent experiments.