Extended Data Fig. 3: Verifying pre-cRNA processing in cells.

a, Representative image of smFISH against crRNA array transcripts in U2OS cells co-transfect with plasmid expressing CRISPR array and GFP alone. Left, crRNA array smFISH spots detected by a single FISH probe (Atto590) that binds the direct repeats of the crRNA array. Right, GFP channel for the same cells in the left panel. Scale bar, 10 μm. b, Representative image of smFISH against crRNA array transcripts in U2OS cells co-transfected with plasmid expressing CRISPR array and GFP-tagged Csm complex. Left, crRNA array smFISH spots detected by a single FISH probe (Atto590) that binds the direct repeats of the crRNA array. Right, GFP channel for the same cells in the left panel. Scale bar, 10 μm.