April 15, 2018 (Vol. 38, No. 8)
Strong Points: Relatively simple user interface; help section and forum
Weak Points: Minimal general background on CRISPR or the CCTop tool
In relatively short order, the CRISPR-Cas9 system for genome engineering has taken the biomedical world by storm. Genome editing is now easier and faster to do than ever before. Critical to the success of CRISPR-mediated genome-editing projects is the design of a single guide RNA (sgRNA) to direct the Cas9 to specific sites within the genome, where it will introduce double-stranded breaks in the DNA. This can be a bit tricky and can easily lead to off-target effects. Fortunately, the CRISPR-Cas9 target online predictor (CCtop) allows researchers to quickly assess the predicted targets of their candidate sgRNA sequences before proceeding with their experiments. The user interface for the tool is straightforward and there is a useful help section on the site. There is also a link to a group forum (via Google Groups) where users can submit and respond to questions.