Mesendogen

Human iPSC reprogramming converts somatic cells into pluripotent cells by introducing defined transcription factors; classic human studies used OCT3/4, SOX2, KLF4, and c-MYC, or OCT4, SOX2, NANOG, and LIN28, and judged reprogramming by embryonic-stem-cell-like morphology, pluripotency-marker expression, normal karyotype, and differentiation into derivatives of the three germ layers. This protocol is framed around non-integrating reprogramming culture, with Sendai virus, episomal plasmids, or synthetic modified mRNA as literature-supported delivery options; Sendai virus is an RNA vector reported to avoid host-genome integration, episomal vectors can generate integration-free human iPSCs, and modified mRNA can reprogram human cells while avoiding genomic modification.

CRISPR-Cas9 editing of human pluripotent stem cells uses a guide RNA to direct Cas9 to a genomic target, where Cas9 creates a double-strand break that is repaired mainly by non-homologous end joining for knockout mutations or by homology-directed repair when a donor template is supplied for precise knock-in or sequence correction. The readout is generated by genotyping edited bulk populations or single-cell-derived clones, using PCR, sequencing, restriction-based assays, reporter fluorescence, or allele-specific analysis to distinguish unedited alleles, indels, precise donor-mediated edits, biallelic deletions, and unwanted on-target lesions.