Amplification of 163 bp fragment of IL-6 promoter using real-time PCR system (left panel) and its restriction digestion to identify the rs1800976 SNP genotype in Pakistani subjects (right panel). A 2% agarose gel stained with ethidium bromide after restriction digestion of amplicon is shown. Lanes M, 50 bp DNA size marker; Lanes 1-7, PCR-RFLP of RA samples showing GG (lanes 1-6) and CC (lane 7) genotypes, respectively.