Notes: The authors compared the performance of four commercially available bisulfite conversion kits and compared their performance on several parameters. During the initial analysis, lambda DNA fragments that were methylated and unmethylated were quantitated and used in known ratios of methylated to unmethylated to test each of the four kits including our MethylEdge™ Bisulfite Conversion System. Conversion efficiency and specificity were tested by using PCR to test for any unconverted DNA from the different kits and sequencing analysis performed on the resulting products. DNA yield was tested by quantitating DNA before and after bisulfite conversion. As a result of these tests, the authors selected MethylEdge™ Bisulfite Conversion System as one of two kits for further analysis. The second test of conversion specificity by sequencing on an Illumina MiSeq platform showed the MethylEdge™ Bisulfite Conversion System had the best performance and was selected to use in analysis of two differentially methylated regions in chorionic villus sample studied previously by the authors. (4577)