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Short answer: CT26 is a mouse colon carcinoma cell line from BALB/c mice, induced with the chemical carcinogen N-nitroso-N-methylurethane (NNMU) and cloned as CT26.WT. It grows adherent in culture, carries a homozygous Kras G12D mutation, and is used as a syngeneic tumor model in BALB/c mice. Its identity is easiest to confirm from its name, species, strain and genotype together.
What a cell line is
Cell line definition
A cell line is a population of cells, taken originally from a tissue or tumor, that has been grown in culture and can be propagated and stored for repeated use. Because every vial of a line descends from the same origin, different laboratories can work with the same biological material. That is the point of naming a line, and it is also why an unclear name or a mixed-up vial causes problems: results are only comparable when the line is the one the paper says it is.
What is the cell line CT26?
CT26 is one such line. The ATCC catalog entry for CT26.WT (CRL-2638) lists the species as Mus musculus, the strain as BALB/c (H-2d haplotype), the tissue as large intestine (colon) and the disease as carcinoma, described as an undifferentiated colon carcinoma cell line. Cellosaurus (CVCL_7254) records the same origin: a female BALB/c mouse, with the tumor transformed by NNMU, citing Brattain et al., Cancer Research 1980. A report on a metastatic colon cancer model describes CT26 as originally developed in 1975.
How CT26 is used in practice
CT26 cells are used as a syngeneic model: the cells come from BALB/c mice, so they can form tumors in immunocompetent BALB/c mice without being rejected as foreign. ATCC reports that subcutaneous injection produces lethal tumors in 80% of BALB/c mice at 103 cells and in 100% at 104 cells. A published orthotopic study used a luciferase-expressing derivative, CT26-luc1, in female BALB/c mice and described the parent line as mildly immunogenic.
A genomic characterization by Castle et al. (BMC Genomics 2014; 15:190) mapped the genome, transcriptome and immunome of CT26. It reports a Kras mutation, a homozygous Cdkn2a deletion, MHC class I expression without MHC class II, and 154 mutations identified as potential immunotherapy targets. The authors state that CT26 cells share molecular features with aggressive, undifferentiated, refractory human colorectal carcinoma cells.
CT26, CT26.WT and the other names for the same line
The literature uses several labels. This table reconciles them using the ATCC, Cellosaurus and published records listed under Sources.
| Item | What the records say | Source |
|---|---|---|
| Name and synonyms | CT26; also written CT-26, CT 26 and Colon Tumor 26. CT26.WT is the cloned wild-type line sold as ATCC CRL-2638 (Cellosaurus CVCL_7256, a child entry of CVCL_7254). | Cellosaurus; ATCC |
| Species and strain | Mus musculus, BALB/c, H-2d | ATCC |
| Sex of donor | Female | Cellosaurus |
| Tissue and histology wording | Large intestine (colon); ATCC says carcinoma, Cellosaurus and published papers say adenocarcinoma | ATCC; Cellosaurus; PMC4604007 |
| Genotype markers | Homozygous Kras p.Gly12Asp (c.35G>A); homozygous Cdkn2a deletion (CT26.WT entry) | Cellosaurus |
| Growth in culture | Adherent; ATCC lists the morphology as fibroblast | ATCC |
| Culture conditions | ATCC-formulated RPMI-1640 with fetal bovine serum to 10%; 37 °C, 95% air and 5% CO2; subculture ratio 1:4 to 1:10; medium renewed every 2 to 3 days | ATCC |
| Storage | Liquid nitrogen vapor phase; ATCC states that storage at -70 °C results in loss of viability | ATCC |
Where it matters for labs and supply decisions
Three points from the vendor record matter when a lab receives or banks this line. First, storage: ATCC specifies liquid nitrogen vapor phase, and the same record says -70 °C storage loses viability, so a freezer-only inventory does not match it. Our guide to cryopreservation media covers the freezing side. Second, medium: ATCC names the base medium and serum percentage, so the medium and serum used should be recorded alongside the line. Third, contamination history: ATCC notes that mycoplasma was detected in a culture submitted in July 2001 and cleared with BM Cycline, with later tests negative, a reminder that mycoplasma status belongs in the routine record for any line; see mycoplasma testing methods compared.
For reporting, cite the line by its registry identifier so readers know which entity was used. The RRID entry and the authentication of key resources entry explain how funders and journals ask for this. Other lines in this series, such as the MC38 cell line and the K562 cell line, use the same identity-first layout.
Common misunderstandings
Carcinoma or adenocarcinoma?
Both appear. ATCC lists carcinoma; Cellosaurus and published papers say adenocarcinoma. They refer to the same line, so check the identifier and genotype rather than the histology word.
Does the fibroblast label mean it is a fibroblast line?
No. ATCC gives the tissue as colon and the disease as carcinoma. The word fibroblast appears as the cell morphology entry.
Is CT26 a human line?
No. It is mouse (BALB/c). Its Kras and Cdkn2a features are compared with human colorectal carcinoma in the literature, but the cells themselves are murine.
Can it be used in any mouse?
The tumor-take figures above are for BALB/c mice. The H-2d background is what makes it syngeneic there, so results in other strains should not be assumed to match.
FAQ
What is a cell line?
A cell line is a population of cells from a tissue or tumor that is grown, propagated and stored in culture so many labs can work with the same material. CT26 is an example derived from a mouse colon tumor.
What is the definition of a cell line, and what are cell lines used for?
Cell lines give researchers a reproducible biological system. Their value depends on knowing exactly which line was used, which is why registries such as Cellosaurus assign identifiers.
What is the CT26 cell line derived from?
A colon tumor induced in a BALB/c mouse with NNMU, later cloned as CT26.WT.
What medium does CT26.WT use?
ATCC specifies ATCC-formulated RPMI-1640 medium with fetal bovine serum to a final concentration of 10%.
Sources
- ATCC, CT26.WT (CRL-2638) product page: https://www.atcc.org/products/crl-2638. Checked 2026-10-29.
- Cellosaurus, CT26 (CVCL_7254): https://www.cellosaurus.org/CVCL_7254, and CT26.WT (CVCL_7256): https://www.cellosaurus.org/CVCL_7256. Checked 2026-10-29.
- Brattain MG et al. Establishment of mouse colonic carcinoma cell lines with different metastatic properties. Cancer Research 1980; 40:2142-2146: https://pubmed.ncbi.nlm.nih.gov/6992981/. Cited via Cellosaurus; checked 2026-10-29.
- Castle JC et al. Immunomic, genomic and transcriptomic characterization of CT26 colorectal carcinoma. BMC Genomics 2014; 15:190. doi:10.1186/1471-2164-15-190: https://pmc.ncbi.nlm.nih.gov/articles/PMC4007559/. Checked 2026-10-29.
- Development of a metastatic murine colon cancer model (PMC4604007): https://pmc.ncbi.nlm.nih.gov/articles/PMC4604007/. Checked 2026-10-29.
