Peer-reviewed articles published by IDT scientists. Filter using one or more categories to focus on specific topics.
This report describes the isolation of a Cas9 variant that displays a superior on- to off-target ratio when delivered in RNP format. Robust on-target editing was achieved at therapeutically relevant loci in hard-to-edit primary cells, while overall off-target editing was substantially reduced. The high-fidelity Cas9 enzyme used in the study is now commercially available from IDT as the Alt-R HiFi Cas9 Nuclease V3.
Researchers from the University of Washington and TwinStrand Biosciences describe a targeted sequencing approach called CRISPR-DS, which couples a previously described method known as duplex sequencing with CRISPR-Cas9 system for target selection. Alt-R CRISPR-Cas9 RNAs were used in in vitro digestion to fragment input genomic DNA at specified locations, followed by size selection. Compared to standard duplex sequencing approach, CRISPR-DS resulted in 20-fold improvement of on-target rate using only minimal amounts of input DNA.
The authors of this paper describe Easi-CRISPR, a robust and efficient strategy for targeted DNA cassette insertion in mice. The international consortium of 7 research teams injected mouse zygotes with long single-stranded DNA donors (Megamer Single-Stranded DNA Fragments) and pre-assembled Cas9 ribonucleoprotein complexes (Alt-R crRNA, tracrRNA, and Cas9 nuclease), and obtained successful knock-in at 13 loci.
In order to operate the International Space Station (ISS) National Laboratory more like an Earth-based lab, NASA has developed a molecular biology suite for microgravity conditions called WetLab-2. WetLab-2 is composed of tools, reagents, and methods, which allow on-orbit processing of biological samples and real-time gene expression analysis in space.
This paper describes the results from the WetLab-2 validation experiments. Specifically, qPCR was performed on a concentration series of DNA calibration standards, and RT-qPCR with ZEN Double-Quenched Probes was conducted on RNA that had been extracted and purified (on-orbit) from frozen E. Coli and mouse liver tissue.
Research scientists from IDT and the Gurumurthy lab (University of Nebraska Medical Center) describe methods for genome editing with ribonucleoprotein RNP complexes, which contain chemically-modified, synthetic guide RNAs and recombinant Cas9 protein. RNP delivery methods are described for lipofection and electroporation in mammalian cells, as well as microinjection in murine zygotes, either with or without addition of single-stranded HDR template DNA.