ppTG21

Gene editing modify specific sites within the genome through gene deletions, insertions or conversions to study functionally unknown genes or conduct gene therapy. It is also used to change the biological traits of organisms to establish new varieties. Gene editing techniques include zinc finger nuclease (ZFN), transcription activator-like effector nuclease (TALEN), and clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas 9) (CRISPR/Cas9).

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.