CRISPR Puzzle Lab Education-Only • Safe
Future: add Cas variants (e.g., Cas12a/TTV).
Forward PAM: NGG Reverse PAM: CCN Click a PAM marker to place your 20-nt gRNA.
Target locus highlighted on tracks
Tip: Zoom with your browser if needed. Each colored marker is a clickable PAM; we’ll compute the 20-nt protospacer adjacent to it (proper strand/orientation).
Current Design
Click a PAM to draft a guide.
Goal
Not Met

On-Target Score
0
GC, motifs, proximity
Off-Target Risk
Seed-weighted mismatches
Level Thresholds
Science note: Seed region (10 nt nearest the PAM) mismatches matter more. We weight them higher in off-target risk.
Top Potential Off-Targets (≤3 mismatches)
Across all toy chromosomes, both strands
# Chr Pos Strand Mismatches Seed mm Seq (20nt)