Immunofluorescent analysis of Cytochrome P450 4A (green) showing staining in the cytoplasm and membrane of H-4-II-E cells. Formalin-fixed cells were permeabilized with 0.1% Triton X-100 in TBS for 5-10 minutes and blocked with 3% BSA-PBS for 30 minutes at room temperature. Cells were probed with a Cytochrome P450 4A polyclonal antibody (Product # PA3-033) in 3% BSA-PBS at a dilution of 1:100 and incubated overnight at 4 ºC in a humidified chamber. Cells were washed with PBST and incubated with a DyLight-conjugated secondary antibody in PBS at room temperature in the dark. F-actin (red) was stained with a fluorescent red phalloidin and nuclei (blue) were stained with Hoechst or DAPI. Images were taken at a magnification of 60x.