How to Use CRISPR-Cas9 to Edit Genes in Human Cells

This patent covers a method for changing how genes work inside eukaryotic cells, like human cells. It introduces an 'engineered, non-naturally occurring' CRISPR-Cas system into the cell (Claim 1). This system uses one or more delivery vehicles called 'vectors' (Claim 1) to bring two main components: a 'guide RNA' and a 'Type-II Cas9 protein' (Claim 1). The guide RNA is designed to find and stick to a specific 'target sequence' on the cell's DNA. Once the guide RNA is attached, the Cas9 protein acts like molecular scissors, cutting the DNA at that precise spot (Claim 1). This cut then alters the 'expression of at least one gene product,' meaning it can turn a gene off, turn it down, or even change its function. For example, this system could be used to silence a gene that causes a specific disease.

The clever bit

The novelty lies in engineering a bacterial defense system (CRISPR-Cas) to work reliably within complex eukaryotic cells, like human cells, to precisely cut DNA at a chosen location using a programmable guide RNA and a Type-II Cas9 protein that do not naturally occur together in that engineered form.

What it does not cover

• ×Does not cover naturally occurring CRISPR-Cas systems where the Cas9 protein and guide RNA exist together without human engineering (Claim 1).
• ×Does not cover gene editing methods that do not involve cleaving the DNA molecule with a Cas9 protein (Claim 1).
• ×Does not cover CRISPR systems that operate outside of eukaryotic cells, such as in bacteria (Claim 1).
• ×Does not cover gene editing techniques that use different types of Cas proteins other than Type-II Cas9 (Claim 1).
• ×Does not cover methods of altering gene expression that do not involve introducing a guide RNA and Cas9 via vectors (Claim 1).