Large-fragment Knockin Rats (ROSA26)

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In order to achieve consistent and predictable ubiquitous gene expression in your rat model, targeted insertion into the ROSA26 locus is an ideal choice. The ROSA26 locus is often referred to as a “safe harbor” locus, and has been extensively used as a transgene insertion site due to the lack of insertion site side effects and the stable ubiquitous expression of genes inserted here. Now, with the application of CRISPR-based knockin technology, large DNA fragments can be accurately introduced into the ROSA26 locus quickly and efficiently, with turnaround times as short as 3 months. We guarantee delivery of 3 animals for fragments up to 2 kb.
Workflow of CRISPR-based Large-fragment Knockin Rats (ROSA26)

Description of Services

ROSA26 large-fragment knockin strategy design

Tell us the gene you wish to knockin and we will design a nuclease-mediated strategy for you. This includes design of the donor vector and gRNA vectors, and selection of target sites in the gene based on our optimized algorithm that maximizes on-target nuclease activity and minimizes off-target activity. Genotyping assays based on PCR and sequencing will also be designed for the screening of founder rats.


Knockin vector construction

DNA vectors that express the desired nucleases will be constructed. Where needed, the efficacy of these vectors will be tested in cell culture.


CRISPR/Cas9 injection into rat eggs

- mRNA preparation: Nuclease expression vectors will be transcribed in vitro. The resulting mRNA will be artificially capped and polyadenylated to facilitate proper translation in mammalian cells.


- Pronuclear injection to obtain founders: The nuclease mRNA will be injected into fertilized rat eggs, followed by implantation of the eggs into surrogate mothers to obtain offspring.


Knockin founder screening

Pups will be screened by PCR to identify knockin founder rats. Specifically, the site targeted by CRISPR will be PCR-amplified to reveal any insertions. Occasionally, an animal may be found to have both alleles of the target site mutated.


Breeding founders to obtain F1

Cyagen will breed up to 3 founders to wildtype rats of matching strain background, and genotype their offspring to obtain F1 rats bearing the large-fragment knockin.

Donor Strain Information

ROSA26 large-fragment knockin is provided on a SD/Long Evans background.

Pricing and Turnaround Time

For projects where nuclease expression vectors are constructed by Cyagen 


Stages Service Price Turnaround time
1 Rosa26 large fragment knockin strategy design  Free 1-4 days
2 Knockin vector construction (up to 5kb fragment) $4,650 4-7 weeks
3  CRISPR/Cas9 injection to obtain knockin founders SD $25,950 8-12 weeks
Long Evans $26,950 8-16 weeks
4 Genotyping pups to identify knockin founders $1,450 2-4 weeks
5 Breeding founders to obtain F1 $3,150 12-18 weeks
6 (Optional) Southern blotting for founders or F1 $3,000 2-4 weeks


Note: Pricing applied to projects with fragments up to 5kb in length. Larger fragments up to 8kb can be accommodated at an additional cost. Please refer to formal quotations for additional information.


Cyagen offers the best guarantee in the industry – we will fully refund the client’s service fee if animals with the specified genotype are not generated (except for genetic modifications severely affecting viability, mobidity, or fertility). Given the complexity of biological systems, a particular genetic modification may not result in the desired phenotype. As such, Cyagen's guarantee covers the creation of animals with the specified genotype, not a particular phenotypic outcome in terms of transcription, protein/RNA function, or organismal biology.

◆ Inquiries and Quote Requests

Request a quote now. Alternatively, you can always email or call 800-921-8930 to inquire about our services or obtain a quote for your project.

Price Matching

If you find another commercial service provider that offers better pricing than ours, we will match the price plus an additional 5% off.

Bulk Discount

We offer up to a 10% bulk discount for large orders. Large orders are defined as 5 or more projects from the same institution. If you bundle your orders with those of your colleagues, you can all qualify for the bulk discount.

◆ Payments

Standard payment terms include a 50% upfront payment before the project, and the remaining 50% plus shipping charge paid after completion of the project. If you need us to design your transgenic strategy, we will provide this service for free irrespective of whether you end up choosing us for your project.

◆ Shipping

Products are shipped from our Santa Clara, California facility. For rat shipments, the shipping charge includes courier cost plus a $100/crate handling fee. DNA constructs or fixed/stained embryos are shipped at room temperature, and the charge includes courier cost plus a $10 handling fee. We typically use World Courier to ship live rats and FedEx for other shipments. 

◆ Animal Programs

All animal work is conducted in our specific pathogen free (SPF) facilities that have been AAALAC accredited and OLAW assured. For details information, please visit our support section for Description of our Facility, Animal Health and Animal Welfare Program.

◆ Customer References

Please click here to view a map of customers who have used Cyagen before worldwide.

◆ Citations

Please click here for a list of publications that have cited Cyagen.