Results of clone sequencing of the 115-bp MethyLight PCR products. The sense-strand sequences of the methylated p16 CpG island with and without bisulfite treatment were listed. The bisulfite-treated template of two 115-bp MethyLight-positive samples was amplified with the same primer set. The PCR products of these two representative samples were clone-sequenced, respectively. 99.6% (223/224) and 93.5% (144/154) cytosines at CpG sites within total 16 and 11 clones (14 CpG sites/clone) from the sample K286 and K285 were maintained and 77.8% (548/704) and 90.9% (440/484) cytosines at non-CpG sites within these clones (44 non-CpG sites/clone) were converted to thymines, respectively. These results indicate that these clones are fully methylated at all CpG sites.
Zhou et al. BMC Medical Genetics 2011 12:67 doi:10.1186/1471-2350-12-67