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This post was updated on Dec 5, 2017.

CRISPR makes it easy to target multiple loci - a concept called multiplexing. Since CRISPR is such a robust system, editing or labeling efficiency doesn’t usually change when you add multiple gRNAs. Sound good? Addgene has many tools to help you multiplex - we’ll use mammalian plasmids to introduce you to some of your potential options and cloning methods, but please scroll down for plasmids suitable for other model systems, including E. coli, plants, Drosophila, and zebrafish!

Having seen CRISPR’s success in basic research, researchers are eager to apply it in a clinical setting. CRISPR is often used for animal germline modification, to repair or add in disease-causing mutations, but, until recently it hadn’t been used to treat disease postnatally. Now, three papers published concurrently in Science have shown CRISPR can treat a genetic disease in a postnatal mouse model, an important proof of concept for future preclinical and clinical work.

In the third installment in our podcast series, we chat with new Addgene Board Member, Michael Koeris. Dr. Koeris did his graduate work in Professor Jim Collins' lab (then at Boston University, now at MIT) where he worked on understanding bacterial antibiotic resistance. During this time, Dr. Koeris and Professor Timothy Lu (a graduate student in the Collins' lab at the time) got the idea to engineer bacteriophage (viruses that infect bacteria) for use as antibiotics. To develop this idea, Drs. Koeris and Lu founded the biotech startup company, Novophage. As you'll hear Dr. Koeris explain however, the time was not right for the development of phage-based therapeutics. After a brief stint at the venture capital firm, Flagship Ventures, Koeris helped change Novophage's focus. The company went from developing therapeutics to developing phage-based tools for detecting pathogens in food products. Along the way, the company changed its name from Novophage to Sample 6.

The advent of CRISPR/Cas9 made it easier than ever to efficiently make precise, targeted genome modifications. Cas9 has been modified to enable researchers to knock out, activate, repress or even image your favorite gene.  But, with such a wide variety of Cas9-based reagents available, how do you choose which Cas9 is right for your particular experiment?  This blog post will help familiarize you with the wide array of Cas9s available through Addgene’s repository and make it easy to select the Cas9 reagent that is right for you.

The first thing to do in any CRISPR experiment is identify what, exactly, you are trying to do.  Are you trying to permanently knock-out a gene in a cell type or organism? Are you trying to reduce expression of a particular gene without permanently modifying the genome?  Does it make more sense to try and activate at a particular locus?  What about modifying the epigenome at a particular location?  As you might expect, the answer to this question will substantially affect your decisions about which Cas9 you need for your experiment.  Below is a brief summary of a few of the common genetic manipulations one can carry out using Cas9 and the specific Cas9s that can be used for each.

One of the best things about sharing plasmids through Addgene is that we provide an added level of confidence in the plasmids we distribute through our quality control processes. Every plasmid we receive is rigorously verified before becoming available to the community.

This is no small task, however, at a repository that consistently receives around 200 new DNA samples every week. Here we will provide an inside look at the steps we take to verify the identity and quality of the plasmids we make available and provide some advice on the steps you can take to verify your own plasmids.