SoylentNews

takyon writes:

CRISPR's MAGESTIC Evolution Makes Gene Editing More Precise

Scientists at the Joint Institute of Metrology and Biology (JIMB)—a collaboration between Stanford University and the National Institute of Standards and Technology (NIST)—have now developed a CRISPR-Cas9–based platform that can make precise, single-nucleotide changes in target DNA at the genome-wide level. The new technology has been dubbed MAGESTIC because it is a "multiplexed, accurate genome-editing" tool that uses "short, trackable, integrated cellular" barcodes. Tests using the MAGESTIC platform to carry out high-throughput, precise gene editing and evaluation in the yeast model Saccharomyces cerevisiae demonstrated fivefold increases in editing efficiency and as well as sevenfold increases in cell survival.

[...] One of the major differentiators of the MAGESTIC platform is that it actively recruits the donor DNA to the double-stranded breaks caused by Cas9 scissors using array-synthesized guide RNA/donor DNA (guide-donor) oligonucleotides. This enables a more than fivefold increase in precision editing efficiency, the authors state. Another of the major features that sets MAGESTIC apart from other multiplexed CRISPR editing approaches is that it uses genome-integrated barcodes that are tagged onto the end of the guide-donor sequence. Using traditional approaches, the barcodes are embedded in the plasmids, which are then inherited by daughter cells and multiply. However, the plasmid barcode system is not completely accurate, and so can give false measures of cell number. Instead, the MAGESTIC platform integrates the barcodes directly into the yeast cell chromosomes, which is a far more stable, easily tracked system, the researchers claim. "...we introduce stable, genome-integrated barcodes instead of plasmid barcodes, thereby enabling marker-free variant tracking and one-to-one correspondence of barcode counts to stain abundance."

Multiplexed precision genome editing with trackable genomic barcodes in yeast (DOI: 10.1038/nbt.4137) (DX)

Original Submission