Figure 5

Morphology of transgene-free induced pluripotent stem cells following conversion to clinical-grade conditions. (A) Conversion of post-excised iPSCs from a xeno-containing substrate, Matrigel, to a xeno-free containing substrate, Synthemax, under current good manufacturing practice (GMP) conditions. (B) Quantitative PCR for pluripotency associated genes displays that pre-converted and post-converted induced pluripotent stem cells (iPSCs) retain normal expression levels across multiple synthetic substrates. (C) Beyond the standard GMP-grade sterility testing, a flow cytometry-based assay for a nonhuman antigen, N-glycolylneuraminic acid, displayed that upon GMP-grade conversion all sialic acid detection was eliminated (1% with post-excised cells on Matrigel down to 0% with post-excised cells in GMP conditions). An iPSC line derived under GMP conditions and mouse embryonic fibroblasts (MEFs) were used as negative and positive controls, respectively. hESC, human embryonic stem cell; hIPSC, human induced pluripotent stem cell; PE CELLstart, post-excised iPSC CELLstart; PE Synthemax, post-excised iPSC Synthemax; PE Matrigel, post-excised Matrigel.