MMRRC ES Cell Clones and Related Cell Lines

Through special agreements with originators, the MMRRC distributes mutant ES cell clones, parental and feeder cell lines. Individual facilities may also provide additional services, such as:

  • supply chimeric mice created by microinjection;
  • breed chimeric mice to establish germline transmission.


An expansion of an ES cell clone is a minimal service and does not include verification of the identity of the ES cell line by DNA sequencing. It usually takes 4-6 weeks to receive the cell line if you choose this option.

As we have occasionally encountered incorrectly identified ES cell clones, we highly recommend confirmatory testing to identify the clone. The following methods can be used to assure the identity of the ES cell clone:

  1. Parental cell lines - background strain microsatellite testing can be performed to assure genetic identity of the mouse strain of origin. This service is available through the MMRRC.
  2. Fluorescent transgenic ES cell lines - PCR assays are provided for the marker transgene. We recommend confirming the presence of the transgene by PCR or examination of the cell line microscopically for fluorescent marker expression.
  3. Gene trap cell lines - The vast majority of Gene Trap cell lines have been correctly identified, as judged by DNA sequencing (i.e., repeat determination of the DNA sequence tag after expansion). However, as pointed out above, incorrectly identified ES cell clones are occasionally encountered. To re-iterate, we strongly recommend that you confirm the identity of your ES cell line. We recommend that you review the Gene Trap Overview , posted on the International Gene Trap Consortium website, with a helpful Gene trapping tutorial, this has information regarding gene trapping technology, including possible Limitations and Pitfalls with trapped clones created by high throughput technologies. We recommend Blasting the Sequence Tag to Estimate the Location of a Gene Trap. Generally you will want to select a clone that traps the furthest upstream. We do offer resequence verification services. Genetic confirmation of a cell line is an add-on service; cost is in in addition to the distribution fees of the cell line itself. Further, all distribution fees and service fees will be applied even if a cell line cannot be genetically confirmed. Expansion plus verification of an ES cell line by DNA sequencing requires up to 3 months. Sequence verification provides confirmation of the original generated sequence tag. In addition, you will still want to do further verifications that your gene of interest is being trapped, such as RT-PCR.
  4. Sanger MicroRNA (miRNA) knockout lines - The majority of Sanger miRNA knockout cell lines have been generated using JM8A3 ES cells, while a small fraction were generated with JM8.F6 ES cells, both of which are derived from the JM8 parental cell line, a C57BL/6N derived mouse embryonic stem cell line. The wildtype JM8.F6 and JM8A3 are available from the KOMP Repository. These miRNA knockout cell lines have been screened by the donor for proper targeting via long range PCR (LRPCR) of the long and short arms. For a small minority of clones it has not been possible to confirm targeting by LRPCR at both ends. This is most likely due to technical failure of the LRPCR rather than improperly targeted clones. For applicable strains this is indicated on the strain detail page accessed through the MMRRC catalog. Relevant PCR data can be found at the IKMC MartSearch. Additionally, in high-throughput processes in which cells are plated on 96-well plates there is a small chance of cell overgrowth leading to a mixture of two different cell lines. Therefore, genetic confirmation is strongly recommended for these cell lines. We offer genetic confirmation services which include LRPCR to confirm proper targeting, vector copy number count, and Y chromosome verification. This service fee is in addition to the mutant cell line fee and requires 8 - 12 weeks for expansion of ES Cells and genetic verification. Genetic confirmation of a cell line is an add-on service; cost is in addition to the distribution fees of the cell line itself. Further, all distribution fees and service fees will be applied even if a cell line cannot be genetically confirmed.

Please see our Fees page.

Three levels of parental ES cell lines are available for E14Tg2a.4 (BayGenomics and Sanger Institute Gene Trap Resource (SIGTR)) and AK7 (Soriano) cell line collections; only Level 2 of parental ES cell line is available for the Nagy collection - see item 2 below:

  1. CTRL. These are high passage wild type parental clones suitable for DNA extraction, control purposes, but not for germline transmission.
  2. CELL. These are low passage wild type parental clones suitable for a single electroporation and germline transmission.
  3. LOW. For both BayGenomics parental ES cell line E14Tg2a.4 (also used for Sanger (SIGTR) lines) and Soriano parental ES cell line AK7, ultra low passage cells suitable for multiple electroporations and germline transmission are available.

Feeder cell lines are also available.

Collection: Parental line ID:
BayGenomics/SIGTR(E14Tg2a.4)-129P2 MMRRC:015890-UCD
Soriano(AK7)-129S4 MMRRC:015891-UCD
Nagy(C2)-C57BL/6 MMRRC:011989-MU
Nagy(D4)-C57BL/6 MMRRC:011990-MU
Nagy(G4)-B6x129S6 MMRRC:011986-MU
Nagy(R1)-129X1x129S1 MMRRC:011978-MU
Nagy(R1/E)-R1 subline MMRRC:011979-MU

Requesting ES cell lines, parental cell lines, or feeder lines, or chimeric mice made with a cell line:

Please use the "Requesting Stocks" navigation tab in the menu bar at the top of this page for information about requesting MMRRC products.