Results of bisulfite-sequencing of the 588 bp fragment of the p16 CpG islands.
(A) Sequences of the methylation-positive and negative clones from the 588 bp unbiased PCR products amplified using a CpG-free primer set and bisulfite-treated genomic DNA templates of two representative gastric carcinoma tissues containing methylated p16 by the 115 bp MethyLight assay ; (B) Sequences of the methylation-positive and negative clones from the 588 bp sMSP products. Purple bars, methylated CpG sites; Blue bars, seeding methylated CpG sites detected in the unbiased PCR products; Green bars, seeding methylated CpG sites used to design the sMSP primers. Each row presents one clone; Clone markers of methylation-positive p16 molecules (containing more than three methylated-CpG sites) are highlighted with blue color. The standard sequence of the fully methylated p16 amplicon and the primer-matched regions in each assay are demonstrated on the top part.