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Short answer: A549 is an established (continuous) human cell line derived from a lung carcinoma, classed by Cellosaurus as lung adenocarcinoma. It is not a primary cell line, it is not small cell lung cancer, and it carries a homozygous KRAS p.Gly12Ser (G12S) mutation. ATCC sells it as CCL-185; the Cellosaurus accession is CVCL_0023.
This page is for researchers deciding whether A549 suits an experiment and how to report it. It is general reference information from the cell-line resources named in the Sources section, read 2026-11-07, not a protocol and not medical advice.
Definition and scope
ATCC describes A549 (CCL-185) as a human, epithelial-like, adherent carcinoma line from lung tissue. The donor was a 58-year-old White male. The cells are hypotriploid with a modal chromosome number of 66. ATCC cites Lieber et al. (1976), “A continuous tumor-cell line from a human lung carcinoma with properties of type II alveolar epithelial cells,” as the original description. ATCC lists the cells as keratin-positive and G6PD isoenzyme B, and as a suitable transfection host.
Cellosaurus (CVCL_0023) records the same line with the disease label lung adenocarcinoma, and lists the synonyms NCI-A549 and A549/ATCC and the common misspellings A59 and A594. It notes the line’s inclusion in NCI-60, DepMap, ENCODE and the Human Protein Atlas, which is why published datasets on it are easy to find.
What type of cancer is the A549 cell line?
Lung adenocarcinoma, according to Cellosaurus. ATCC labels it a lung carcinoma. The two descriptions are consistent: carcinoma is the broad class and adenocarcinoma is the specific histology Cellosaurus assigns.
What are small cells in lung cancer?
The National Cancer Institute states that lung cancer has two main types: non-small cell lung cancer and small cell lung cancer. Small cell lung cancer is a separate disease category, named for the appearance of the tumor cells. A549 is an adenocarcinoma line, so it is not a small cell lung cancer model and should not be used as a stand-in for one.
Is A549 a primary cell line?
No. A primary culture is taken directly from tissue and has a limited lifespan. A549 is an established line that ATCC and Cellosaurus both describe as a continuous tumor-cell line, propagated since the 1976 paper cited above. That has practical consequences: it grows reliably and is widely shared, but it has accumulated genetic changes (hypotriploid karyotype) and does not represent normal alveolar epithelium.
Is A549 a KRAS mutant?
Yes. Cellosaurus records KRAS p.Gly12Ser (c.34G>A) as homozygous. It also records a homozygous STK11 p.Gln37Ter change, no reported TP53 mutation, and microsatellite-stable status. ATCC’s product page does not state KRAS status, so cite Cellosaurus (or primary sequencing data) for genotype rather than the catalog page. If your question depends on KRAS or LKB1 (STK11) biology, or on intact p53, confirm that this combination fits your hypothesis.
How A549 is used in practice: culture facts from ATCC
These values are ATCC’s published recommendations for CCL-185; your supplier’s sheet is authoritative for your lot.
- Medium: F-12K with 10% fetal bovine serum.
- Atmosphere: 37 °C, 95% air and 5% CO₂.
- Passaging: rinse with D-PBS, detach with trypsin-EDTA, split 1:3 to 1:8; seed at 2×10³ to 1×10⁴ cells/cm² and do not exceed 7×10⁴ cells/cm². Renew medium two to three times a week.
- Doubling time: about 22 hours (ATCC).
- Freezing: complete medium with 5% DMSO, stored in vapor-phase liquid nitrogen rather than at -70 °C.
Handle the line according to your institution’s biosafety assessment.
Where it matters: a reporting and authentication checklist
Most A549 papers look alike, so reproducibility comes down to documenting what you actually used. Each item below maps to a fact in the sources.
| What to record | Why, from the sources |
|---|---|
| Supplier and catalog number (for example ATCC CCL-185) | ATCC is the repository for CCL-185; Cellosaurus also lists the line as A549/ATCC. |
| Cellosaurus accession CVCL_0023 (as RRID:CVCL_0023) | Cellosaurus is the source database for CVCL_ identifiers; see RRID. It also separates A549 from the misspellings A59 and A594. |
| Medium and serum | ATCC specifies F-12K plus 10% FBS; other media are used in the literature. |
| Doubling time you measured | ATCC gives about 22 h; Cellosaurus records literature values of roughly 18 to 40 h depending on medium and source, so a single quoted figure is not transferable. |
| Short tandem repeat (STR) profile | ATCC publishes a reference STR profile for CCL-185 (for example TH01 8,9.3 and vWA 14), the basis for checking identity. |
| Mycoplasma status | ATCC reports mycoplasma not detected at lot QC; test your own stocks. See mycoplasma testing methods compared and cell culture contamination. |
| Passage or population-doubling level | A continuous line changes over time, so give the passage used. Related record numbers are covered in cell culture reference numbers. |
Common misunderstandings
- “A549 represents normal lung.” It is a tumor-derived line with mutated KRAS and STK11; the Lieber et al. title describes properties of type II alveolar epithelial cells, not normal tissue.
- “Lung cancer line means small cell.” Small cell lung cancer is a different NCI-defined type; A549 is an adenocarcinoma.
- “The catalog page gives the genotype.” ATCC does not state KRAS status; Cellosaurus does.
- “22 hours is the doubling time.” It is ATCC’s figure under its conditions; the literature range is wider.
Related lab guides
For other molecular workflows that often use cultured lines, see what is an RNA extraction kit and gene knockout.
Frequently asked questions
Is A549 a KRAS mutant?
Yes: Cellosaurus lists homozygous KRAS p.Gly12Ser (G12S).
What are small cells in lung cancer?
Small cell lung cancer is one of the two main lung cancer types named by the National Cancer Institute, the other being non-small cell. A549 is an adenocarcinoma line, not a small cell model.
What type of cancer is the A549 cell line?
Lung adenocarcinoma (Cellosaurus); ATCC classifies it as a lung carcinoma.
Is A549 a primary cell line?
No. It is an established, continuous tumor-cell line.
Sources
- ATCC, A549 (CCL-185) product page, https://www.atcc.org/products/ccl-185, read 2026-11-07.
- Cellosaurus, A549 (CVCL_0023), https://www.cellosaurus.org/CVCL_0023, read 2026-11-07.
- National Cancer Institute, Lung cancer, https://www.cancer.gov/types/lung, read 2026-11-07.
- Lieber M, et al. 1976, A continuous tumor-cell line from a human lung carcinoma with properties of type II alveolar epithelial cells (as cited by ATCC).
