How to Use Many CRISPR Guides to Study Many Genes at Once

This patent describes a method to use a large collection of CRISPR-Cas9 guide RNAs to target and modify many different genes or DNA regions across a population of eukaryotic cells, enabling high-throughput genetic screening.

What it covers

This patent describes a system for simultaneously studying many genes in living cells using CRISPR-Cas9. It involves a "composition" (Claim 1) of eukaryotic cells, like embryonic stem cells (Claim 2), that contain a "library" of 100 or more "guide RNAs." Each guide RNA is designed to target a "unique genomic locus" (Claim 1), meaning a specific spot in the cell's DNA. When these guide RNAs are introduced into the cell population, along with the Cas9 protein (Claim 11), they can direct the Cas9 to cut or modify many different genes. For example, this system can be used to create "knockout mutations" (Claim 5) in thousands of unique genes (Claim 17) to see how each gene affects a specific "pathway" like the immune system (Claim 7) or cell division (Claim 10).

What it doesn't cover

• —Does not cover using CRISPR-Cas9 to target only a single specific gene in a cell, as the claims require a 'library' targeting a 'plurality of target sequences' (Claim 1).
• —Does not cover methods using fewer than 100 guide RNAs in the library (Claim 1 specifies '100 or more').
• —Does not cover gene editing in prokaryotic cells (like bacteria) or other non-eukaryotic organisms (Claim 1 specifies 'eukaryotic cells').
• —Does not cover CRISPR systems that do not use Cas9 protein, as the claims specifically mention 'CRISPR-Cas9 system guide RNAs' and 'Cas9 protein' (Claim 1, Claim 11).
• —Does not cover gene editing methods where the Cas9 protein is not directed by a guide RNA for sequence-specific binding (Claim 11).

The clever bit

The novelty lies in combining a large "library" of guide RNAs with a population of cells, enabling the simultaneous targeting of hundreds or thousands of unique genomic locations. This allows for parallel testing of many gene functions, rather than laboriously testing one gene at a time.

Why it matters

This patent is significant because it enables large-scale, systematic studies of gene function. Before this, understanding the role of every gene in a complex biological process was incredibly difficult and time-consuming. By providing a framework for high-throughput CRISPR screening, it allows researchers to quickly identify which genes are involved in diseases, drug responses, or fundamental biological pathways. This accelerates drug discovery and basic scientific understanding.

Real-world examples

• 1.CRISPR-based drug target discovery platforms
• 2.Functional genomics screens in academic research
• 3.Research into cancer resistance mechanisms
• 4.Studies of immune system pathways
• 5.High-throughput genetic screens for essential genes