There’s a new development for CRISPR-Cpf1 genome editing! A recent paper from Feng Zhang's lab describes how to use Cpf1 for multiplex genome editing. For a few reasons, Cpf1 is a simplified system for editing multiple targets compared to Cas9. Read on to learn more about Cpf1 multiplexing. For an in-depth review of Cpf1, check out this blog post or see Addgene's CRISPR guide page for a review of Cas9. For a brief comparison of Cpf1 vs. Cas9, see the table below.
This Post was updated on May 3, 2017 with additional information and resources.
This post was contributed by guest blogger, Addgene Advisory Board member, and Associate Director of the Genetic Perturbation Platform at the Broad Institute, John Doench.
CRISPR technology has made it easier than ever both to engineer specific DNA edits and to perform functional screens to identify genes involved in a phenotype of interest. This blog post will discuss differences between these approaches, as well as provide updates on how best to design gRNAs. You can also find validated gRNAs for your next experiment in Addgene's Validated gRNA Sequence Datatable.
This post was contributed by the gene editing team at the Allen Institute for Cell Science. Learn more by visiting the Allen Cell Explorer at allencell.org and the Allen Institute website at alleninstitute.org.
A classic challenge in cell biology is making sure that what we observe through the microscope represents reality as accurately as possible. This is especially true in the case of protein tagging to elucidate cellular structures. Overexpression methods flood the cell with protein, which can both interfere with a cell’s normal function and result in a ubiquitous background signal that makes it hard to visualize the precise location of the protein or structure of interest.
Endogenous gene tagging is an ideal solution because it allows for tagging and visualization of specific, individual proteins under endogenous regulatory control. But even with the advent of CRISPR/Cas9 technology, inserting large tags into a precise location in the genome is still inefficient, particularly in human cell lines. Furthermore, the quality control necessary to ensure the edited cells are behaving normally can be prohibitively expensive for many labs.
We all know that in the lab there are often little tricks that are essential for experiments but that nobody talks about. After months of troubleshooting, those people who did not tell you that essential thing ask incredulously, “You seriously didn’t add 3 microliters of 5 mM star anise?” This is something I was expecting when I set out to make my first CRISPR/Cas9 gene edit. I wanted to inactivate the gene BRAF (a kinase implicated in several human cancers) in A549 cells (a human lung cancer cell line), armed only with viruses obtained through Addgene’s viral service and the methods sections of scientific articles (gasp). To my delight, not only was I able to make the edits without any reagent-grade endangered Martian chicory root, but considering this is a needle in a haystack type of objective, it was surprisingly easy. It’s true, I CRISPRed. In this post, I’ll summarize the basic steps and analyses, and give what I think are the main tips for each step of performing and analyzing a gene edit using Addgene’s lentiviral CRISPR tools.
Colorful CRISPR technologies are helping researchers visualize the genome and its organization within the nucleus, also called the 4D nucleome. Visualizing specific loci has historically been difficult, as techniques like fluorescent in situ hybridization (FISH) and chromosome capture suffer from low resolution and can’t be used in vivo. Some researchers have used fluorescently tagged DNA-binding proteins to label certain loci, but this approach is not scalable for every locus...unlike CRISPR. Early CRISPR labeling techniques allowed researchers to visualize nearly any single genomic locus, and recent advances have allowed scientists to track multiple genomic loci over time using all the colors of the CRISPRainbow.