Guide-RNA Off-Target Risk Scanner

Designing a CRISPR guide RNA is not just about picking a sequence next to the target gene — it is about checking that no other place in the genome looks similar enough for the Cas9 complex to cut there by mistake. This simulator runs a genome-wide sequence-alignment search live: the guide slides across a synthetic genome one position at a time, and every position is scored by how many of its 20 bases mismatch the guide. Switch between a poorly-designed guide, which turns up several near-identical off-target sites scattered across the genome, and a well-screened guide, which was specifically chosen because the same search found nothing but the correct on-target site — and watch the live risk-score readout track the difference in real time.