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Short answer
K562 is a human cell line established by Lozzio and Lozzio from the pleural effusion of a 53-year-old female with chronic myelogenous leukemia. ATCC lists it as K-562 (CCL-243), a suspension line of lymphoblast morphology. Papers also call it erythroleukemic, and the same line carries several names, so reports should state the source and identity checks.
Definition and scope: what is a cell line?
A cell line is a population of cells from one origin that can be grown and passaged in culture over many generations, so different labs can work on the same biological material. The same definition is applied on the sibling guides for THP-1, MC38 and PC12, and this page is about K562 specifically. The wider field context is in what is cell biology, which includes cell line authentication.
What K562 is
The ATCC product page (CCL-243) gives the core description: Homo sapiens, bone marrow, chronic myelogenous leukemia, lymphoblast morphology, growing in suspension. ATCC quotes the original establishment as being from “the pleural effusion of a 53-year-old female with chronic myelogenous leukemia” and describes the cells as “highly undifferentiated and of the granulocytic series”.
Cellosaurus (entry CVCL_0004, updated 25 June 2026, version 55) records the donor as female, 53 years old, with blast-phase CML that is BCR-ABL1 positive, and describes the fusion as BCR exon 14 fused to ABL1 exon 2 (b3a2 transcript). It also records a homozygous TP53 p.Gln136fs*13 variant. ATCC reports a triploid stemline chromosome number, tumorigenicity (including in nude mice), and CD7 at 25%.
How it is described and used in practice
ATCC’s stated culture conditions are ATCC-formulated Iscove’s Modified Dulbecco’s Medium (30-2005) with fetal bovine serum to a final concentration of 10% (30-2020), at 37 °C in 95% air and 5% CO2. For freezing, ATCC specifies complete growth medium with 5% DMSO, stored in the vapor phase of liquid nitrogen below -130 °C. ATCC lists mycoplasma, bacteria and fungi as not detected in its quality control, and names STR profiling or whole-genome sequencing as verification methods.
Cellosaurus labels K-562 among the “ENCODE project common cell types; tier 1”, which is one reason it appears in so many genomics datasets, and lists many engineered K-562 child lines derived from it.
K562 identity card: one line, several names
| Item | What the source records | Source |
|---|---|---|
| Preferred name and synonyms | K-562; also K562, K.562, K 562, KO, GM05372, GM05372E | Cellosaurus |
| Misspellings listed in databases | “K-652” and “K652” | Cellosaurus |
| Catalog entry | ATCC CCL-243 | ATCC |
| Origin | Pleural effusion, 53-year-old female, chronic myelogenous leukemia | ATCC; Cellosaurus |
| Molecular marker | BCR-ABL1 (b3a2 transcript) | Cellosaurus |
| Growth | Suspension; lymphoblast morphology | ATCC |
| Original publications | Lozzio and Lozzio 1975, Blood; Andersson et al. 1979, Int J Cancer | Cellosaurus |
The two original publications explain a common source of confusion. The 1975 paper is titled “Human chronic myelogenous leukemia cell-line with positive Philadelphia chromosome”, while the 1979 paper is titled “K562 — a human erythroleukemic cell line”. That is why some papers call K562 a CML line and others an erythroleukemia line: both labels trace to the line’s own literature.
Where it matters for labs: sources and STR profiles differ
Cellosaurus lists STR profiles for K-562 from many repositories, including ATCC CCL-243, DSMZ ACC-10, RCB1635, CLS 300224 and JCRB0019, and some loci differ between them. For D3S1358 the DSMZ profile is 14,16 and the ATCC profile is 16. For D18S51 the CLS profile is 15, ATCC is 15,16 and DSMZ is 16. ATCC’s own profile includes Amelogenin X, CSF1PO 9,10, D13S317 8, D16S539 11,12, D5S818 11,12, D7S820 9,11, TH01 9.3, TPOX 8,9, vWA 16, D21S11 29,30,31, D8S1179 12 and FGA 21,24.
The practical consequence of this comparison is limited to reporting: record which repository or lab supplied the line, and which reference profile an authentication result was compared with, because matching to a different repository’s profile can look like a mismatch at the loci above. The authentication of key resources entry explains the funder expectation, and the RRID entry covers the identifier format; Cellosaurus accessions use the CVCL_ prefix (for K-562, RRID:CVCL_0004 follows that format).
Common misunderstandings
“K562 is an erythroleukemia line, not a CML line.”
Both labels exist. ATCC and Cellosaurus describe the donor as having chronic myelogenous leukemia (blast phase), and the 1979 paper’s title uses “erythroleukemic”.
“All K562 stocks are identical.”
Repository STR profiles differ at some loci, and Cellosaurus lists many engineered K-562 child lines. State the source, the passage and any modification.
“K562 grows attached to plastic.”
ATCC lists the growth properties as suspension.
“K652 and K562 are two lines.”
Cellosaurus lists “K-652” and “K652” as misspellings of the name.
FAQ
What is a cell line?
A population of cells from a single origin that can be maintained in culture through repeated passaging. See the THP-1 guide for the definition and scope applied to a second line.
What is the definition of a cell line?
Cells of one origin kept growing in culture so that many labs can work with the same material; a cell line is identified by its name, species, tissue of origin and, ideally, an authentication profile.
What is the K562 cell line?
A human line from a 53-year-old female with chronic myelogenous leukemia, catalogued by ATCC as CCL-243 and carrying the BCR-ABL1 fusion.
Is K562 adherent?
No. ATCC lists its growth properties as suspension.
What is the cell line K562 called in databases?
K-562, with synonyms K562, K.562, K 562, KO, GM05372 and GM05372E recorded in Cellosaurus.
Sources
- ATCC, K-562 (CCL-243) product page, https://www.atcc.org/products/ccl-243, checked 2026-10-29.
- Cellosaurus, K-562 (CVCL_0004), https://www.cellosaurus.org/CVCL_0004, entry updated 25 June 2026 (version 55), checked 2026-10-29.
- Lozzio CB, Lozzio BB. Human chronic myelogenous leukemia cell-line with positive Philadelphia chromosome. Blood, 1975; listed in the Cellosaurus K-562 entry, https://www.cellosaurus.org/CVCL_0004, checked 2026-10-29.
- Andersson LC, et al. K562 — a human erythroleukemic cell line. Int J Cancer, 1979; listed in the Cellosaurus K-562 entry, https://www.cellosaurus.org/CVCL_0004, checked 2026-10-29.
