Oxford Genetics’ custom CRISPR-Cas9 libraries are available in either a pooled or an arrayed format. The libraries comprise a Cas9 expression plasmid, each containing a guide RNA (gRNA) toward a different target gene, supplied in either a plasmid or lentiviral particle format. These can then be delivered into cells using standard transfection reagents or through transduction, enabling rapid, effective knockout of target genes, and making them suitable for typical screening work flows. The libraries are constructed on demand using gRNA designs produced in collaboration with Desktop Genetics, which incorporates the latest developments in research to select the optimal gRNA designs, or you can supply your own gRNA designs and we can take care of the rest. The gRNAs can be inserted into any of our Cas9 expression plasmids and the full list of these can be found here.


Why Work With Oxford Genetics

  • 60 Cas9 Expression Plasmids - Provide the widest choice of options for your custom library project
  • 100% Guide Representation - A fully automated production platform ensures full confidence in design and production
  • Flexible Guide Coverage - Allows you to set the number of guides per gene
  • Latest gRNA Designs - All our libraries are made on demand using the latest design algorithms from Desktop Genetics
  • Plasmids or Lentiviral Formats - Ensures effective delivery into various cell types
  • Pooled or Arrayed Libraries - Available in fully customizable sizes, including subpools to suit the various screening work flows
  • Rapid Design and Production - Libraries are delivered ready to use in 8 to 10 weeks


CRISPR Plasmid Choices

This figure illustrates the various elements of the SnapFast CRISPR plasmid portfolio.


Overview of Crispr Vector


CRISPR Library Formats

Oxford Genetics CRISPR libraries are available in multiple formats as individual plasmids in tubes, as custom arrayed libraries in 96 well plates, and as pooled and sub-pooled libraries in tubes. This allows complete cutomization in terms of the number of guides and the format.


Individual Guides


Arrayed Libraries


Pooled Libraries

1 gRNA


48 - 95  gRNAs (1 x 96 well plate)


Small: 200 - 1000 gRNAs

2 – 5 gRNAs


96 gRNAs (1 x 96 well plate)


Medium: 1,001 - 10,000 gRNAs

6 – 15 gRNAs


480 gRNAs (5 x 96 well plates)


Large: 10,001- 50,000 gRNAs

16 – 25 gRNAs


960 gRNAs (10 x 96 well plates)


Extra Large: 50,001 - 150,000 gRNAs

26 – 48 gRNAs


4800 gRNAs (50 x 96 well plates)





Guide Representation

The quality of guide representation in a CRISPR-Cas9 library is used to assess the quality. The critical steps in ensuring effective guide representation is dependent on the quality of DNA synthesis followed by the efficiency of the cloning methodology.

To demonstrate the quality of Oxford Genetics custom library generation a custom guide design in collaboration with Desktop Genetics with a total library size of 4,440 guides was cloned via an homology based method into a standard Cas9 expression vectors and assessed.



In Summary the results were as follows:

  • 95% guide variants within a uniformity of <5
  • 0% dropouts (i.e. no missing guides)
  • 2.31% runaways (outside 10-fold range)
  • Median guide presence approx. 100X


Additional Services


DNA Design

Oxford Genetics has expertise in creating custom plasmids for various applications. So if you require novel Cas9 expression plasmids talk to us.

Cell Line Development

Oxford Genetics has expertise generating stable, recombinant, cell lines expressing heterologous products, such as proteins or viruses. So if you require a cell line stably expressing Cas9 talk to us.

Cell  Line Engineering

Oxford Genetics has expertise in the genome editing of mammalian cell lines. So if you require a knock-out or knock-in cell line talk to us.