CRISPR miss the whole genome

CRISPR-Cas genes are among the most popular editing tools. Recently, the Massachusetts General Hospital (MGH) research team has developed a new method for detecting CRISPR off-target effects in the genome-wide, GUIDE-seq (Genome-wide Unbiased Indentification of DSBs Evaluated by Sequencing). The results published in the journal Nature Biotechnology on December 16 in.

"People in the past when it detects CRISPR-Cas nuclease-induced off-target DNA breaks, often presupposes off target sites and target sites similar .GUIDE-seq is the first method does not need to do so, but it is quite sensitive," This senior author of the study, associate professor at Harvard Medical School, said J. Keith Joung. "This is very important for the clinical assessment of CRISPR-Cas security."

Guiding CRISPR-Cas RNA nuclease (RGN) by disconnecting the double-stranded DNA to introduce genetic changes, RGN Cas contain a nuclease and a short RNA sequence complementary to the target DNA. Joung, who first reported last year, when the difference between the target fragment of DNA fragments in five nucleotides, CRISPR-Cas RGN will be off target. Such off-target mutation can cause side effects, including cancer, to identify and reduce these CRISPR DSB is to ensure that the foundation of clinical safety.

The researchers used a short double-stranded oligonucleotides to mark CRISPR-Cas-induced off-target fracture, sequencing these genomic regions where the label, it is possible to determine the location of off-target mutation. Studies have shown that even the appearance of an off-target mutation frequencies as low as 0.1%, GUIDE-seq also been able to detect. Because Human Haptoglobin ELISA Kit http://www.cusabio.com/ELISA_Kit-83112/ in a large off-target and target site local differences, so off-target DSB number and position is difficult to predict.