Figure 7.

Colocalization of BLM, BRCA1, and RAD50 with PCNA following treatment with HU. Cells were left either untreated or exposed to 1 mm HU for 7 hr. Then, cells were fixed by methanol/acetone treatment and stained by indirect immunofluorescence with the following primary antibodies: (A–F) anti-PCNA (PC10, Santa Cruz) and anti-BRCA1 (Ab-2, Neomarkers); (G–L) anti-PCNA (PC10, Santa Cruz) and anti-BLM; (M–R) anti-PCNA (FL261, Santa Cruz) and anti-RAD50 (GeneTex). Appropriate Cy3- or FITC-conjugated secondary antibodies were used and confocal images were captured at 1260× magnification. It should be noted that the majority of cells after HU treatment did not appear significantly different from the untreated cells. However, ∼10% showed redistribution into nuclear foci as represented in these images.