Methylation-specific PCR

Genomic DNA was extracted and subjected to bisulfite modification as described previously.²⁹ Briefly, 2 μg of genomic DNA was denatured with 0.2 M NaOH at 37 °C for 10 min and treated with 10 mM hydroquinone and 3 M sodium bisulfite (pH 5.0) at 50 °C for 16 h. Modified genomic DNA was analyzed with methylation-specific PCR SOCS3 primers as described.¹³ The positions and sequences of the primers are shown in Supplementary Figures 15a and b.