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Short answer: HEK293 is an adherent human cell line derived from embryonic (fetal) kidney and transformed with human adenovirus 5 DNA. It is catalogued as ATCC CRL-1573, and 293T is a highly transfectable derivative that carries the SV40 large T antigen. Both are routine hosts for transfection, but they differ in recommended medium, biosafety wording and use, so record which one you hold. This page is general cell-culture reference, not medical advice.
Definition and scope
Cellosaurus entry CVCL_0045 describes HEK293 as a female Homo sapiens line from human embryonic kidney, transformed with human adenovirus 5 DNA, and classes it as a transformed cell line. Its synonyms include 293, HEK-293, HEK 293, Graham 293 and Human Embryonic Kidney 293. The ATCC product page for CRL-1573 describes epithelial, adherent cells that are hypotriploid with a modal chromosome number of 64, and names F. L. Graham as depositor (checked 2026-11-07).
Transformed cells and transformation
In this context, a transformed cell is one whose growth properties were altered by introducing foreign genetic material; for HEK293 that material is adenovirus 5 DNA. ATCC notes the line is tumorigenic in nude mice. This differs from transfection, the routine introduction of a plasmid into cells, which is the main reason labs use HEK293 (see transfection methods, controls and biosafety).
What are human HEK293 cells used for in practice?
The 293T derivative is described by ATCC (CRL-3216) as a highly transfectable derivative of HEK 293 that contains the SV40 T antigen and is competent to replicate vectors carrying the SV40 origin. Cellosaurus lists hundreds of derivatives, including 293T, 293-F, Flp-In-293, HEK-Blue reporter lines and CRISPR knockouts. For a transfection reagent example, see polyethylenimine (PEI) transfection; for virus production, see the lentiviral transduction guide.
HEK293 versus 293T: a sourced comparison
| Feature | HEK293 (ATCC CRL-1573) | 293T (ATCC CRL-3216) |
|---|---|---|
| Origin | Human embryonic kidney, adenovirus 5 DNA | Derivative of HEK 293 with SV40 T antigen |
| Growth medium listed by ATCC | EMEM + 10% FBS | DMEM + 10% heat-inactivated FBS + 2 mM L-glutamine |
| Freezing medium listed by ATCC | Complete medium + 5% DMSO | Growth medium + 5% DMSO |
| Storage after freezing | Liquid nitrogen vapour phase (not -70 °C) | See the product sheet |
| Subculture (ATCC) | 1:6 to 1:10 weekly; renew medium every 2-3 days | See the product sheet |
Source: ATCC product pages CRL-1573 and CRL-3216, checked 2026-11-07. Suppliers other than ATCC may specify different media.
Which DMEM for HEK cells?
There is no single answer: ATCC lists EMEM for HEK-293 and DMEM (with heat-inactivated FBS and 2 mM L-glutamine) for 293T, so the correct medium is the one on the cell bank sheet for your exact line. See DMEM vs RPMI for how the basal media differ and cell culture basics for general handling.
How to freeze HEK293 cells?
The ATCC product information specifies complete growth medium with 5% DMSO as the freezing medium and storage in the vapour phase of liquid nitrogen rather than at -70 °C. Use the cell bank’s current sheet for the full protocol; treat these settings as the supplier-stated baseline.
Where it matters: authentication and biosafety
- Name the line precisely. Cellosaurus lists synonyms (293, HEK-293, Graham 293) and misspellings to search for, including HECK293, HEK239, HK293, HEK-393 and HEK393. Record the Cellosaurus identifier (CVCL_0045 for HEK293) in methods text and sample records.
- Do not assume a derivative is plain HEK293. Cellosaurus notes doubt that the producer line used for the Sputnik V (Gam-COVID-Vac) vaccine is a standard HEK293 and suggests it is probably an engineered derivative.
- Biosafety. ATCC assigns HEK-293 biosafety level 2 because it contains adenovirus sequences. The wording on the 293T page is inconsistent between sections, so confirm the level on the current product sheet and with your institutional biosafety committee.
- Contamination checks. See mycoplasma testing methods compared.
Common misunderstandings
- HEK293 and 293T are not the same line: they are related but listed separately, with different catalogue numbers and recommended media.
- “HEK cells” is not one line; the name covers many lines and derivatives.
- Transformed does not mean transfected; one describes a line’s origin, the other an experimental step.
FAQ
What are human HEK293 cells?
An adherent human embryonic kidney cell line transformed with adenovirus 5 DNA (Cellosaurus CVCL_0045; ATCC CRL-1573).
What are the three types of cell lines?
Sources group lines in different ways. Cellosaurus assigns each line a category, and HEK293 sits in “transformed cell line”. Check the category recorded for your own line.
How to freeze HEK293 cells?
ATCC specifies complete medium with 5% DMSO and vapour-phase liquid nitrogen storage; follow the supplier sheet.
Which DMEM for HEK cells?
ATCC lists DMEM with 10% heat-inactivated FBS and 2 mM L-glutamine for 293T and EMEM for HEK-293; use your supplier sheet.
Sources
- Cellosaurus, HEK293 (CVCL_0045): cellosaurus.org/CVCL_0045, checked 2026-11-07.
- ATCC, HEK-293 (CRL-1573): atcc.org/products/crl-1573, checked 2026-11-07.
- ATCC, 293T (CRL-3216): atcc.org/products/crl-3216, checked 2026-11-07.
