gRNA
Also written as: gRNA — guide RNA
A synthetic RNA molecule that directs the Cas nuclease to the correct genomic target sequence. May also appear as 'sgRNA' (single guide RNA) in experimental reports.
Full Definition
A guide RNA (gRNA) is a short, engineered RNA that combines a target-specific CRISPR RNA (crRNA) sequence with a transactivating crRNA (tracrRNA) scaffold into a single molecule. It base-pairs with a complementary DNA sequence adjacent to a protospacer adjacent motif (PAM), guiding the Cas nuclease for site-specific cleavage. Editors will encounter both 'gRNA' and 'sgRNA' in manuscripts; the terms are often used interchangeably but sgRNA technically refers to a single, fused guide molecule. Consistency of usage within a document should be enforced. The term is lowercase in running text: 'the gRNA was designed to target exon 3'.
Usage
Usage note: Lowercase in text. 'gRNA' and 'sgRNA' are often used interchangeably but are not strictly synonymous; flag inconsistencies for author clarification.
In Context
- "Four gRNAs were screened to identify the most efficient target site within the BRCA1 locus." — Results section
- "The gRNA sequence must be verified against the reference genome to exclude off-target sites." — Peer review comment