NF-κB reporter assay

1 μg NF-κB luciferase reporter vector were transfected in RAW264.7 macrophages along with 0.5 μg pCMV-β-gal in serum free medium using Lipofectamine (Invitrogen) according to manufactures instruction. Cells were harvested using reporter lysis buffer (Promega, Madison, WI, USA) and NF-κB luciferase activity was assessed by luminometer. The value of luciferase activity was normalized to transfection efficiency and this was monitored by the co-transfected β-galactosidase expression vector.