the Laslett lab samples (R=0.59), which was the only lab positively correlated with use of the original medium used to maintain hESCs (“originalES”, R=0.63) (Thomson et al., 1998). This lab-specific effect can therefore be explained by the use of originalES medium, which is the highest correlating variable with DIRAS3 aberrations (R=0.82). L3MBTL aberrations were most significantly correlated with the Keirstead lab samples (R=0.75). The samples from the Keirstead lab used in this analysis consisted of 2 isogenic clones, which were both passaged in collagenase and grown in Wicell-conditioned medium on Matrigel™ (R=0.74). As theses samples were nearly perfectly correlated with these concurrent variables (R=0.99), this lab-specific effect for L3MBTL can almost entirely be explained by technique and/or cell line of origin. The association of PEG3 aberrations with the Loring lab samples (Bonferroni adjusted p<0.001, R=0.42) could not be attributed to any particular manipulation, but most likely results from an overrepresentation of HDF51 hiPSC clones that were derived from the same fibroblast culture in the same experiment and comprise 70% of all Loring lab samples in the model.
