Cas9

CutSite

Find the fluorescing target. Snip it before the window closes.

Score 0
Combo ×1
Time 30
Difficulty 0%
Load a guide RNA to begin
Accuracy: —
Guide RNA 5′--3′

Ready to edit a genome?

A short stretch of DNA will light up next to its PAM site, the signal Cas9 uses to know where to cut. Click the glowing target as fast as you can. Speed and streaks multiply your score.

Cutting anywhere else is an off-target edit: the combo resets and, when Cas9 would have refused the site, the blades jam.

Guide RNA mode lights up decoys too. Read the guide and cut only the site that matches it beside a real NGG PAM. Sites face either way: a PAM to the left of a glow marks a bottom-strand site, read right to left.

Daily: twelve targets, the same for everyone today. Your first finished run counts; copy the result to compare with your lab.

Keyboard works too: arrows move along the strand, J or 1–3 jump to a glowing site, Enter cuts, Esc ends a Zen or Daily round.