Campbell and Moorehead BMC Cancer 2011, 11:480 http://www.biomedcentral.com/1471-2407/11/480 Page 9 of 13 Figure 5 PDGFR knockdown inhibited cell migration in IGF-IR-independent recurrent cells. PDGFRa and b were knocked down transiently using siRNA alone or in combination 48 h after plating either RJ348 or RJ423 cells (depicted in a and b respectively). Four hours later a pipette tip was used to scratch a wound down the middle of the cultured cells (time 0 h, depicted above). Images were captured at 40 × magnification using an inverted bright field microscope at varying time points after the scratch was made. Representative results are shown; the assay was repeated four times. Scale bars = 1 mm.