To determine if hESC derivation methods may affect imprinted gene methylation, we performed an independent analysis on 40 samples from 34 hESC lines that were derived in the same lab from embryos of different quality, at varying days post-fertilization (D.P.F), and using two different methods (bisection vs. whole embryo plating). The only correlation that we found was that aberrations in the methylation status of PEG3 were weakly associated with earlier D.P.F and whole embryo plating (Bonferroni adjusted p<0.05) (Table S7F).
