Fitc conjugated anti cytokeratin antibody

For immunostaining, the DC2 cells were cultured on an 8-chamber slide (Lab-Tek, Nunc Inc. Naperville, Illinois), then washed twice with PBS and fixed in precooled (−20°C) 100% methanol solution for 2 min. Cells were then washed again twice with PBS and air-dried prior to storage at −20°C until use. The fixed cells were serially hydrated for 15 min with PBS, then treated with PBS pH 7.2 containing 1% SDS for 4 min at room temperature. The slides were washed twice with PBS for 5 min then incubated with PBS containing 1% (w/v) BSA (Sigma, St-Louis, MO) for 15 min. The fixed cells were incubated with FITC-conjugated anti-cytokeratin antibody (1:100, F3418, Sigma, St-Louis, MO) overnight at 4°C in a moist chamber. Cells were then washed twice in high salt PBS (PBS containing 2.7% (w/v) NaCl) for 5 min and then washed twice with PBS for 5 min. DAPI mounting medium (VectaShield, H-1200, Vector Laboratories, Burlingame, CA) was used prior to coverslip application and immunofluorescence-stained samples were examined with a Zeiss Axioskop 2 epifluorescence microscope (Carl Zeiss Canada).