Plasmids and viral vectors are traditionally used in CRISPR genome editing to express the required proteins. However, there is a risk to use DNA instead of mRNA: double stranded DNA breaks catalyse insertion of DNA at the cut site. At some substantial frequency, the protein expression vectors can integrate, which can lead to continuous expression of the nuclease or a previously silent sequence. Now mRNA is becoming a powerful tool in genome editing. With no risk of insertional mutagenesis, mRNA are used to transiently express the required proteins.

Wild-type Cas9 mRNA is a stabilised non-immunogenic messenger RNA (mRNA) that has been designed to produce high expression level of wild-type Cas9 protein. It creates a double stranded break at a target site delineated by RNA guide sequences.

Site specific CRE recombinases are useful tools for manipulation of genomes. However, continued expression of a recombinase in a cell or in vivo can result in toxicity and undesired off-target recombination. For this reason, transient expression from mRNA is an ideal method for recombinase expression.

Cas13 mRNA has been designed to produce high expression level of class 2 type VI-D CRISPR-Cas13d system derived from Ruminococcus flavefaciens XPD3002, a recently discovered RNA-guided RNA endonuclease.

There mRNA are produced by in vitro transcription, stabilised at the 5’ end by modified nucleotides capping and contain a poly(A) tail at the 3’ end. Modified versions are optimised to yield improved stability and performance and to lower the cellular innate immunity response.

• No need of nuclear uptake - protein expression directly in cytoplasm
• Faster protein expression than DNA transfection
• No genomic integration
• Perfect for transfecting slowing or non-dividing cells
• Protein expression in a total promoter-independent manner
• Transient transfection: mRNA based expression of proteins sustains for a limited time
• Shipped on dry ice - storage at -80°C