Lab Code Registry: Frequently Asked Questions


1. What is a Laboratory Code?

A laboratory code (also “laboratory registry code” or “lab code”) contains one to five letters and identifies the institute, laboratory, or investigator that produced and/or maintains a particular animal strain. A lab code is generated when a new model is created and becomes part of that model's nomenclature. Substrains, congenics, and other strains where several otherwise distinguishable forms exist should also be identified by laboratory codes. DNA loci, chromosomal aberrations, and some types of mutations may have lab codes. (Reference:

The Laboratory Code Registry is located here.

Lab code examples:

J   The Jackson Laboratory
Rl   W.L. and L.B. Russell
Jr   John Rapp
Mcw   Medical College of Wisconsin
Kyo   Kyoto University

2. Do I need a lab code to search the Lab Code Registry?


3. I received an email regarding a lab code registration. What is this?

Animal model facilities such as Jackson Laboratories often request lab codes for new strains. Model information is obtained from recent scientific literature or when a new model transfers to an animal facility. In either case, the facility staff may register a lab code with the primary investigator as the point of contact.  

4. What does it mean when a lab code is “retired”?

A lab code can never be deleted or reassigned because the original code may be perpetuated in the nomenclature of many generations of lab animals.

ILAR occasionally changes a lab code’s status to “retired” if the lab code was never used (e.g., two lab codes were inadvertently registered.)

A retired lab code may have its status returned to “active” upon request.

5. Our primary investigator has two lab codes. Can one lab code be retired?

Yes, but only if the lab code was never used. The lab code will continue to be used if it designates a strain that transferred to another laboratory.

6. What if the investigator’s strain was transferred to someone else?

The lab code does not change if the strain continues to be maintained at the same institution. In this case, you should send the updated contact information to ILAR.

If the strain is transferred to a new facility, the receiving investigator or institution should request a new lab code that will be appended to the existing registration (e.g., if a strain A/J held by Jackson Laboratory were transferred to and maintained at Kyoto University, its name would become A/JKyo).

7. What should we do if our organization registered several lab codes, but the primary investigators left?

If the animal colony remains at your facility, please send the updated contact information to ILAR. The original investigator’s lab code will be retained in the strain name.

8. Our investigator recently submitted another lab code. We now have two lab codes for the same strain. Can we delete the second code?

No, a lab code can never be deleted. ILAR will retire the most recently submitted lab code upon request.

9. I entered the wrong lab code for our primary investigator. Can I enter a new one and delete the old one?

You may register a new lab code but the original lab code cannot be deleted. ILAR will retire the lab code entered in error upon your request.

10. Can a laboratory register multiple lab codes?

Yes. A lab code is meant to identify one of several possible situations:

A) An institutional lab code identifies the organization where the animal colony was originally developed. These animal colonies belong to and are maintained by the institution; they do not move with an investigator. (An institution can have several lab codes depending on institutional preferences.)

B) Alternatively, investigators may register lab codes for animal colonies they own and will take to another institution. Upon moving to the new institution, the investigator should forward updated contact information to

11. What does it mean when a lab code is “Pending” ?

“Pending” status means that your registration is undergoing review prior to being activated. This process may take a week or more.

A lab code may also remain “pending” if there is insufficient contact information or the code is formatted incorrectly. ILAR will activate the lab code after these items are addressed.

Contact ILAR at if there is an extended delay in processing your registration.

12. Our institution changed its name. Should we retire the current lab code(s) or make changes to the current lab code(s)?

There is no need to retire the code. Send the institution’s new name (and any other changes) to ILAR.

13. Is there a way to list all the investigators associated with one lab code?

No. The system is not set up to list multiple investigators. An institutional lab code that covers multiple investigators can be assigned to the institution, but not to individual investigators.

14. I manage several colonies and have several primary investigators. When submitting a lab code, how do we avoid using only one investigator’s name?

Lab codes are most frequently registered for a facility instead of an individual investigator. In this case, you may submit one contact per facility. Individual investigators’ lab codes refer to a particular colony -- exclusive of other colonies at the same institution.

15. The contact information in our lab code is incorrect. Can ILAR update this information?

Yes, send the updated information to


16. An investigator moving to another institution wants to register a lab code. Should s/he register under their current address and contact ILAR to update the record later, or wait until s/he has moved to register?

The investigator should send new contact information to ILAR upon the colony’s arrival at the new institution.

If the investigator moves and the colony is associated with an institutional lab code, send ILAR the new contact information for the holding institution. (The institution should request a lab code and append it to the investigator’s lab code if the colony was associated with an individual lab code.)

If the investigator moves and begins breeding a "new" animal colony and their personal lab code is assigned to the strain, and the code remains appended to the strains in the colony . If the colony is identified by an institutional code, the investigator should register a new code at the new facility or use the lab code of the new facility if one already exists.

[Note: If the investigator has the only strains in the colony that will move, then it is not considered a new breeding colony. If the investigator takes a breeding pair and leaves the original strain behind, then the strains in the two separate colonies will become substrains and need to be distinguished from each other by adding the appropriate lab code.]

17. How do we include the lab code in the name of several strains of the same model (e.g., Wistar )?

Lab codes differ between inbred strains and outbred stocks. Lab codes for inbred stock are appended to the strain name (e.g., C57BL/6Lab code), but in the latter case of outbred stocks it precedes the stock name, followed by a colon (e.g., lab code:Wistar). Where there are several strains or stocks they will, of course, have different designations, but all should have the same laboratory code.

18. We developed a particular animal model many years ago and submitted a lab code for that animal model. Since then we have maintained it by brother x sister mating. Do we keep the original lab code or should we use our facility lab code?

Outbred: If originally developed from an outbred stock that has undergone >20 generations of brother x sister mating then it is a new inbred strain and should be named according to the nomenclature for inbred strains.

Inbred: If already a designated inbred strain, it becomes a separate substrain and should have the existing lab code appended or a new lab code if one is not available because of the length of time the strain has been maintained.

You may continue to use the same lab code as long as an inbred strain remains in your breeding colony. You should register additional lab codes only if you, your institution, or another investigator maintain separate breeding colonies.

19. A 15% genetic variation was found between the samples and the control in an animal colony. What is the proper lab code reference for published study results?

The two colonies are regarded as substrains. If both are held by the same institution or investigator, append serial numbers to the lab code to distinguish them.

20. Will I get a certificate for a lab code?


21. Can you remove my email address from the registry so it isn’t visible to the public?

Yes, contact ILAR to request the removal of your e-mail address.

22. Where are the nomenclature guidelines for transgenic and knockout rodent strains?

Rules and Guidelines for Nomenclature of Mouse and Rat Strains

Rules for Nomenclature of Genes, Genetic Markers, Alleles, and Mutations in Mouse and Rat