May 15, 2016 (Vol. 36, No. 10)


Strong Points: Easy-to-use, good instructions page
Weak Points: Not all gene ID forms work with tool


These days, life scientists can’t seem to avoid the term “CRISPR” even if they wanted to. Understandably, there is a lot of excitement surrounding this technique and its applications to animal models of research and human disease. One of the first steps of using CRISPR is to identify the target sites for mutagenesis in your gene of interest. To help with that, researchers at Harvard University have created the online tool CHOPCHOP. CHOPCHOP is an easy-to-use tool that identifies optimized target sites for both CRISPR- and TALEN-mediated mutagenesis. Users begin by entering a gene ID, a specified region of the genome (maximum 20,000 bases), or a target sequence. Results are displayed in a table, with the target sequence, genomic location, exon, strand GC content percentage and number of identified off-targets provided. Advanced search options include the ability to restrict target sites to a particular region of the gene, as well as some CRISPR- or TALEN-specific options.