# If red blood cells don't contain DNA, how can blood be used for DNA tests? **URL:** \ **Category:** Factual Questions\ **Created:** [March 22, 2025, 8:54pm UTC](https://boards.straightdope.com/t/if-red-blood-cells-dont-contain-dna-how-can-blood-be-used-for-dna-tests/1015963 "2025-03-22T20:54:16Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![Northern\_Piper](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/northern_piper/32/5304_2.png) [@Northern\_Piper](https://boards.straightdope.com/u/Northern_Piper)\ **Post date:** [March 22, 2025, 8:54pm UTC](https://boards.straightdope.com/t/if-red-blood-cells-dont-contain-dna-how-can-blood-be-used-for-dna-tests/1015963/1 "2025-03-22T20:54:16Z")
The wikipedia article on [red blood cells](https://en.wikipedia.org/wiki/Red_blood_cell) says that they don’t contain DNA: > Because of the lack of nuclei and organelles, mature red blood cells do not contain [DNA](https://en.wikipedia.org/wiki/DNA) and cannot synthesize any [RNA](https://en.wikipedia.org/wiki/RNA) (although it does contain RNAs),[[57]](https://en.wikipedia.org/wiki/Red_blood_cell#cite_note-Kabanova2009-57)[[58]](https://en.wikipedia.org/wiki/Red_blood_cell#cite_note-Jain2022-58) and consequently cannot divide and have limited repair capabilities.[[59]](https://en.wikipedia.org/wiki/Red_blood_cell#cite_note-Molecular_biology_of_the_cell-59) But I thought blood samples are one of the means to conduct dna tests at crime scenes? What am I missing? ---
**Author:** ![IvoryTowerDenizen](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ivorytowerdenizen/32/17937_2.png) [@IvoryTowerDenizen](https://boards.straightdope.com/u/IvoryTowerDenizen)\ **Post date:** [March 22, 2025, 8:56pm UTC](https://boards.straightdope.com/t/if-red-blood-cells-dont-contain-dna-how-can-blood-be-used-for-dna-tests/1015963/2 "2025-03-22T20:56:10Z")
Blood contains other cells in addition to red blood cells, such as white cells, which do contain DNA. ---
**Author:** ![FrenchDunadan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/frenchdunadan/32/5449_2.png) [@FrenchDunadan](https://boards.straightdope.com/u/FrenchDunadan)\ **Post date:** [March 22, 2025, 8:56pm UTC](https://boards.straightdope.com/t/if-red-blood-cells-dont-contain-dna-how-can-blood-be-used-for-dna-tests/1015963/3 "2025-03-22T20:56:18Z")
It is in the blood plasma, not in the red cells themselves. ---
**Author:** ![kenobi\_65](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kenobi_65/32/13178_2.png) [@kenobi\_65](https://boards.straightdope.com/u/kenobi_65)\ **Post date:** [March 22, 2025, 8:56pm UTC](https://boards.straightdope.com/t/if-red-blood-cells-dont-contain-dna-how-can-blood-be-used-for-dna-tests/1015963/4 "2025-03-22T20:56:36Z")
> [@Northern\_Piper](#): > > What am I missing? That white blood cells _do_ contain DNA; that may be what is used for such tests. ---
**Author:** ![markn\_1](https://avatars.discourse-cdn.com/v4/letter/m/f9ae1b/32.png) [@markn\_1](https://boards.straightdope.com/u/markn_1)\ **Post date:** [March 22, 2025, 8:59pm UTC](https://boards.straightdope.com/t/if-red-blood-cells-dont-contain-dna-how-can-blood-be-used-for-dna-tests/1015963/5 "2025-03-22T20:59:08Z")
[Neoteryx](https://www.neoteryx.com/microsampling-blog/can-you-get-dna-from-dried-blood), a company that sells blood sampling equipment, says > DNA can be extracted from various blood components, with **white blood cells (WBCs)** being the primary source due to their high nuclear DNA content. Unlike red blood cells, which lack nuclei, WBCs contain intact genetic material, making them ideal for DNA-based studies. Plasma and serum can also contain **cell-free DNA (cfDNA)** , which is particularly valuable in non-invasive prenatal testing (NIPT), cancer research, and infectious disease studies. ---
**Author:** ![Northern\_Piper](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/northern_piper/32/5304_2.png) [@Northern\_Piper](https://boards.straightdope.com/u/Northern_Piper)\ **Post date:** [March 22, 2025, 8:59pm UTC](https://boards.straightdope.com/t/if-red-blood-cells-dont-contain-dna-how-can-blood-be-used-for-dna-tests/1015963/6 "2025-03-22T20:59:53Z")
Thank you all. As Dickens says, “We must have blood, you know.” ---
**Author:** ![md-2000](https://avatars.discourse-cdn.com/v4/letter/m/9d8465/32.png) [@md-2000](https://boards.straightdope.com/u/md-2000)\ **Post date:** [March 23, 2025, 6:57am UTC](https://boards.straightdope.com/t/if-red-blood-cells-dont-contain-dna-how-can-blood-be-used-for-dna-tests/1015963/7 "2025-03-23T06:57:51Z")
But as Portia said, “not one drop…”