Supplementary MaterialsSupplementary Info Supplementary Information srep08973-s1. 12 pluripotent cell lines and 31 non-pluripotent cell lines. Furthermore, DNAm changes at these three CpGs were tracked in the course of differentiation of iPSCs towards mesenchymal stromal cells. The Epi-Pluri-Score does not give info on lineage-specific differentiation potential, but it provides a simple, reliable, and powerful biomarker to support high-throughput classification into either pluripotent or non-pluripotent cells. The possibility of reprogramming somatic cells into induced pluripotent stem cells buy K02288 (iPSCs) offers revolutionized stem cell study1. However, only a portion of cells are successfully transformed into pluripotent state by current reprogramming strategies and most of the cells remain non-pluripotent or partially reprogrammed2,3. Pluripotent stem cells are capable to differentiate into any somatic cell of the body, whereas incompletely or partially reprogrammed cells may even form cells of all three buy K02288 germ layers but do not show all the characteristics of completely pluripotent cells C therefore, by definition, pluripotency can only be verified by adequate assays4,5. On the other hand, tetraploid complementation or chimera formation, which have been founded for the murine system, are not relevant for human being buy K02288 iPSCs. Therefore, alternate methods are usually applied to classify cell preparations more vaguely into pluripotent and non-pluripotent cells: The teratoma assay is definitely often considered as platinum standard for pluripotency screening of human being iPSCs, but it was recently criticized for honest issues and lack of standardization6. Furthermore, practical markers C such as differentiation assays towards all three germ layers C are relatively time- and labor-intensive. Staining of molecular markers (e.g. OCT4, NANOG, TRA-1-60) via immunofluorescence imaging or circulation cytometry are regularly performed, but do not provide quantitative info7,8. Manifestation of pluripotency-associated genes can be assessed by quantitative RT-PCR9,10. However, gene expression is definitely highly dependent on cell growth and requires cutoffs that are not easy to standardize. On the other hand, it is possible to use more complex bioinformatics assays based on whole genome gene manifestation profiles. For example, PluriTest offers proven to be a powerful and highly standardized animal free alternative to the teratoma assay11, but the required microarray profiles are still relatively expensive for high-throughput analysis of individual clones. Thus, there’s a trade-off between cost- or time-intensiveness and reliability constantly. Furthermore, most of the above mentioned methods cannot distinguish between ESCs or iPSCs, and embryonal carcinomas or parthenogenic ESCs. Cellular differentiation is reflected by the epigenetic makeup. The DNA-methylation (DNAm) levels at individual CpGs C usually referred to as beta-values (-values) C can vary continuously between non-methylated (0% DNAm) and methylated (100% DNAm). It has been shown that pluripotent cells have a unique and characteristic epigenetic signature that reflects their broad developmental potential12. Hence, analysis of -values may provide a good measure for molecular definition of iPSCs. Many groups have demonstrated that DNAm profiles of pluripotent stem cells differ considerably in comparison to other cell types13,14,15. iPSCs converge to a characteristic ground state that closely resembles that of embryonic stem cells (ESCs)16,17,18, although it has also been shown that iPSCs retain a residual epigenetic memory’ of their tissue of origin18,19. Within the last years, many well-curated datasets on iPSCs and ESCs have been deposited in public data repositories, which provide new opportunities for identification of epigenetic biomarkers20. In this study, we have systematically compared DNAm profiles of cells that were either classified by the authors as pluripotent (ESCs and iPSCs) Vegfa or non-pluripotent cells to select specific CpG sites that facilitate best discrimination. We hypothesized that two CpGs might.