Immunofluorescent analysis of Endostatin (green) showing positive staining in the secretion of NIH-3T3 cells (right) compared with a negative control in the absence of primary antibody (left). Formalin-fixed cells were permeabilized with 0.1% Triton X-100 in TBS for 5-10 minutes, blocked with 3% BSA-PBS for 30 minutes at room temperature and probed with an Endostatin polyclonal antibody (Product # PA1-601) in 3% BSA-PBS at a dilution of 1:200 and incubated overnight at 4 ºC in a humidified chamber. Cells were washed with PBST and incubated with a DyLight 488-conjugated goat-anti-rabbit IgG 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 DAPI for 5-10 minutes in the dark. Images were taken at a magnification of 60x.