Latest Posts

All Posts

CRISPR-Cas14: a family of small DNA-targeting enzymes enabling high-fidelity SNP genotyping

Posted by Benoit Giquel on Nov 29, 2018 8:53:18 AM

Before being adapted by scientists to edit the genome of virtually any organisms on this planet, CRISPR-Cas systems were merely adaptive immune systems that provide bacteria protection against infectious agents. Several enzymes behind this immunity have already been discovered and studied but it is only the tip of the iceberg as it has been predicted that many others are still unknown.

In this quest to discover new and maybe more efficient Cas systems, Jennifer Doudna’s lab analyzed metagenomic datasets to try to determine whether simpler and maybe smaller Cas systems could exist in nature.

Read More >

Topics: CRISPR, Cas Proteins

Finding nucleic acids with SHERLOCK and DETECTR

Posted by Alyssa Cecchetelli on Aug 30, 2018 8:28:06 AM

Sensitive and specific nucleic acid detection is crucial for clinical diagnostics, genotyping, and biotechnological advancements. Current methods of nucleic acid detection however, either lack the sensitivity or the specificity to detect nucleic acids at low concentrations and/or are too expensive, time-consuming, and complex to use outside of standard laboratories. Recently scientists have utilized CRISPR-Cas9 protein variants, Cas13, and Cas12a, to develop simple, portable, and inexpensive platforms to reliably detect nucleic acids at the atomolar level.

Read More >

Topics: CRISPR, Cas Proteins, Other CRISPR Tools

Cas13d: Small RNA-targeting CRISPR enzymes for transcriptome engineering

Posted by Mary Gearing on May 3, 2018 9:48:09 AM

RNA-editing Cas13 enzymes have taken the CRISPR world by storm. Like RNA interference, these enzymes can knock down RNA without altering the genome, but Cas13s have higher on-target specificity. New work from Konermann et al. and Yan et al. describes new Cas13d enzymes that average only 2.8 kb in size and are easy to package in low-capacity vectors! These small, but mighty type VI-D enzymes are the latest tools in the transcriptome engineering toolbox.

Read More >

Topics: CRISPR, Cas Proteins

xCas9: Engineering a CRISPR Variant with PAM Flexibility

Posted by Mary Gearing on Mar 28, 2018 2:52:13 PM

In order to bind DNA, Cas9 and other CRISPR enzymes require a short PAM sequence adjacent to the targeted sequence at the locus of interest. SpCas9’s 3’ NGG PAM occurs frequently in GC-rich genomes, but a PAM is not always available near the locus you’d like to modify. To tackle the PAM problem, researchers have engineered alternative Cas9s binding distinct PAM sequences. Now, Hu et al., working in David Liu’s lab, have gone one step further, using directed evolution to create xCas9, an enzyme recognizing a broad range of PAMs like NG, GAA, and GAT, but also displaying increased editing specificity. We’re excited to learn more about xCas9 - here’s what we know so far!

Read More >

Topics: CRISPR, Cas Proteins

CRISPR 101: Cas9 Nickase Design and Homology Directed Repair

Posted by Mary Gearing on Mar 15, 2018 8:59:40 AM

By mutating one of two Cas9 nuclease domains, researchers created the CRISPR nickase. Nickases create a single-strand rather than a double-strand break, and when used with two adjacent gRNAs, can lower the probability of off-target editing. But that’s not all! New research from IDT (Integrated DNA Technologies) has shown that a nickase approach can improve homology directed repair (HDR) rates, provided you follow some simple design rules described below.

Read More >

Topics: CRISPR, CRISPR 101, Cas Proteins

Click here to subscribe to the Addgene Blog
 
Subscribe

 

All Topics

see all

Recent Posts