immunodeficient rat model

SD-Rag2tm2hera Il2rgtm1hera

The SRG™ rat (SD-Rag2tm2hera Il2rgtm1hera ), contains a knockout of both the Rag2 and Il2rg genes on the Sprague Dawley background.  This newly created immunodeficient rat model has a severely impaired immune system lacking B-cells, T-cells, and NK-cells. The SRG rat overcomes the limitations of less immunodeficient rat models and provides enhanced utility in comparison to immunodeficient mouse models including demonstrating high tumor take rates and favorable growth kinetics for both xenografts and PDX models.

Now Available for Preorder!


The SRG™ rat was created by Hera BioLabs through targeted-nuclease mediated gene disruption of the II2rg and Rag2 genes on the Sprague Dawley background.  It contains a 8 bp deletion in the Rag2 gene leading to a defective V(D)J recombination which prevents T cell and B cell development.  It also has a 16 bp deletion in the Il2rg gene, which leads to a lack of cytokine signaling, resulting defective lymphoid development. The combined mutations result in a loss of mature  B, T, and NK cells.


The SRG™ rat has a Severe Combined Immuno-Deficiency phenotype. Download the characterization white paper using the link below.

SRG Data Sheet


The SRG™ rat is immunodeficient and ideal for the engraftment of human tissues. This includes xenografts, patient derived xenografts (PDXs), and tissue humanization of the liver and humanization of the immune system.  The SRG™ rat has been validated with a wide range of xenograft/PDX models and consistently demonstrates high tumor take rates with traditionally difficult to engraft cell lines, such as the VCaP prostate cancer cell line, H358 non-small cell lung cancer (NSCLC) , HCT116 colon cancer cell line, and more.  Subcutaneously implanted xenografts and PDX tumors can grow to over 30,000 mm3 in volume compared to 4,000 mm3 in the mouse.

The humanized liver SRG™ rat is currently under development.  Hera has a proprietary rat liver ablation method, which allows for the implantation and expansion of human primary hepatocytes. This model has applications in identifying human specific liver toxicity, pharmacology and infectious disease (HIV, HVC, etc). Hera currently provides services in humanized mouse models. 

The humanized immune system (huIS) is achieved through engraftment and reconstitution of the immune system with human cells.  Hera is developing several methods for humanization of the immune system including using PBMCs and CD34+ hematopoietic stems cells.  This model is ideal for immuno-oncology studies when paired with human xenograft/PDX tumor engraftment.

Growth Chart

Facility Description

Health reports available by request.

The SRG rats will be available for preorder shortly. Please contact us for more information about our preorders waitlist.

Inquire for pricing of different age ranges, bulk pricing, and for non-profit/academic users.

Conditions for Use

Breeding of the SRG rats is strictly prohibited.  Hera requires all customers to sign the terms of the Conditions for Use Agreement prior to shipping the animals. 

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Hera BioLabs AACR Advances in Modeling Cancer Conference Poster

Frequently Asked Questions

Is breeding allowed?  No, breeding is prohibited under the Hera Conditions for Use for the SRG rats. If your study requires breeding of the animals, please contact us.

Can you provide older/younger animals? Currently our standard age at shipment is 4-5 weeks old.  Hera can accommodate requests for any age animals. Contact your representative to discuss your specific requirements.  Additional fees may apply.

When can I expect my order? The SRG rats will be available for pre-order starting November 1st. The animals will be reserved on a first-come first-serve basis starting in December. Upon placing the order your estimated arrival date will be provided and updated monthly.

How are the animals housed?  The SRG rats are housed in Innovive dual HEPA filter individually ventilated caging (IVC) in Hera’s new barrier facility.  Health reports are available for the SRG rats and Hera facility.

Do the SRG rats require a special diet? Are there any additional health concerns? Standard irradiated rodent chow is used. Their immunodeficient phenotype leads to a susceptibility to opportunistic pathogens which should be taken into consideration, as is the case with any immunodeficient strain.  Other than that, the SRG does not require any special diet or have any additional health concerns.

Download Fact Sheet