Figure 1.

The two library protocols generating bisulfite-converted reads. Cokus et al's experimental protocol uses two amplification steps for generating bisulfite-converted sequences and for high throughput sequencing. The bisulfite-converted reads are preceded by one of two tags in the first 5 nucleotides of reads. Lister et al's protocol generates bisulfite libraries using premethylated adapters, and in this case no tags are present.