Figure 1. Genotypic analysis of the Nco1 RFLP. A 782-bp fragment of the TNFβ gene, including the first intron, was amplified by PCR. The PCR product was digested with Nco1 endonuclease. Lanes 1–3: TNFB1 homozygous genotype (TNFB1/B1). Lane 1: Undigested PCR product. Lane 2: Nco1-digested PCR product (2 hours, 37°C). Lane 3: Nco1-digested PCR product (4 hours, 37°C; addition of 10 U Nco1 endonuclease at t = 0 and t = 2 hours). Lanes 4–6: TNFB2 homozygous genotype (TNFB2/B2). Lane 4: Undigested PCR product. Lane 5: Nco1-digested PCR product (2 hours, 37°C). Lane 6: Nco1-digested PCR product (4 hours, 37°C; addition of 10 U Nco1 endonuclease at t = 0 and t = 2 hours). Lanes 7–9: Heterozygous genotype (TNFB1/B2). Lane 7: Undigested PCR product. Lane 8: Nco1-digested PCR product (2 hours, 37°C). Lane 9: Nco1-digested PCR product (4 hours, 37°C; addition of 10 U Nco1 endonuclease at t = 0 and t = 2 hours). Lane 10: Control (PCR without chromosomal DNA).