---
title: "Your blood draw still runs on a 1949 patent"
locale: "en"
url: "https://irz.fr/en/articles/vacutainer-vacuum-blood-collection-en"
markdown_url: "https://irz.fr/en/articles/vacutainer-vacuum-blood-collection-en.md"
category: "ideas"
tags: ["medical", "phlebotomy", "design history", "engineering", "vacutainer"]
published_at: "2026-08-25T16:10:00.000Z"
author: "Camille Morel"
translation: "https://irz.fr/fr/articles/vacutainer-vacuum-blood-collection-fr.md"
---

# Your blood draw still runs on a 1949 patent

A factory-calibrated vacuum acts as pump, meter and seal at once: a teardown of the closed system behind most routine blood draws, built on a patent filed in 1947.

The needle stays in the arm, yet there is no syringe. No plunger to pull, no vial to fill by hand. The phlebotomist pushes a first tube into the holder, blood rises into it on its own, then she swaps that tube out and clips in another one. Three or four tests, a single puncture.

The motor is missing from the picture because it lives inside the tube: a vacuum calibrated at the factory. The principle was patented in 1949 and it still anchors routine blood draws: as Hackaday notes, if you get blood taken today, there's a good chance it ends up in one of these evacuated tubes.[1](https://hackaday.com/2026/08/24/tech-in-plain-sight-vacuum-blood-collection/) BD even claims 84 people per second have blood taken with its Vacutainer products.[2](https://news.bd.com/Celebrating-75-years-of-Evolution-and-Impact-BD-Vacutainer-R-Blood-Collection-Tubes) That number comes from the manufacturer, so read it as marketing, but it points at the obvious truth anyway: this gesture is everywhere.

## One vacuum, three jobs

An evacuated tube looks like a plain sterile vial sealed with a rubber stopper, with its air removed during production. That single vacuum does three kinds of work.[1](https://hackaday.com/2026/08/24/tech-in-plain-sight-vacuum-blood-collection/)

First, pumping: pressure inside the vein exceeds pressure inside the tube, so blood rushes in the moment a needle pierces the stopper. Then, metering: the volume drawn depends on the initial vacuum level, fixed once and for all at manufacture. Standard volumes arrive without electronics, without graduations to read, without adjustments. Finally, sealing: when the tube is full, pressures equalize and flow stops; when the tube leaves the needle, the stopper reseals itself over the puncture.[1](https://hackaday.com/2026/08/24/tech-in-plain-sight-vacuum-blood-collection/)

The other end of the chain matters just as much. The double-ended needle sits in a plastic holder, its rear half wrapped in a soft rubber sleeve: while no tube is engaged, nothing leaks; push a tube in, the stopper gets pierced and blood flows.[1](https://hackaday.com/2026/08/24/tech-in-plain-sight-vacuum-blood-collection/) That self-sealing sleeve took years to get right, and it ended up in American courts: in BD's dispute with Sherwood Medical, the appeals court noted that a 1958 patent for a self-retracting sleeve, made possible by a material developed at Shell Chemical, was enough to make the later patents obvious.[9](https://law.resource.org/pub/us/case/reporter/F2/516/516.F2d.514.72-3599.html)

These tubes are single use, labeled to stay with the patient, and they carry an expiration date precisely because the vacuum can fade in storage.[1](https://hackaday.com/2026/08/24/tech-in-plain-sight-vacuum-blood-collection/)

## A bedside observation

The story starts in a hospital room. Joseph Kleiner, a mechanical engineer, watched his terminally ill wife endure repeated punctures: back then each test meant another needlestick, and transferring blood from the syringe into test tubes often spilled it.[2](https://news.bd.com/Celebrating-75-years-of-Evolution-and-Impact-BD-Vacutainer-R-Blood-Collection-Tubes)

During World War II, the US military already shipped transfusion blood in sealed evacuated containers. Kleiner transposed that wartime logistics onto diagnostics: a closed system that draws straight into the right container.[2](https://news.bd.com/Celebrating-75-years-of-Evolution-and-Impact-BD-Vacutainer-R-Blood-Collection-Tubes)

The timeline deserves a careful telling, since sources disagree. Per the Smithsonian, Kleiner joined BD as early as 1943 bringing his ideas for a collection system, and the company was already marketing the Vacutainer by 1945; the patent was filed in 1947 and granted on February 1, 1949 as US 2,460,641, the same year the trademark arrived.[3](https://americanhistory.si.edu/collections/object/nmah_730875)[2](https://news.bd.com/Celebrating-75-years-of-Evolution-and-Impact-BD-Vacutainer-R-Blood-Collection-Tubes) BD then notes the move to plastic tubes in 1961 and, after the AIDS epidemic, the Hemogard closure designed to limit accidental contact with handled blood.[2](https://news.bd.com/Celebrating-75-years-of-Evolution-and-Impact-BD-Vacutainer-R-Blood-Collection-Tubes)

Three quarters of a century later, the core has not moved: one vacuum, one stopper, one sheathed needle.

> Timeline
> **From an idea to a global gesture**
> - Kleiner joins BD with his project.: 1943
> - Sales already underway.: 1945
> - Patent filed.: 1947
> - Patent granted, trademark registered.: 1949
> Sources: Smithsonian NMAH; BD Newsroom.

## Color means chemistry

The stopper color is not decoration. It announces the additive inside the tube, and that additive decides what your blood can still say once it reaches the lab.[1](https://hackaday.com/2026/08/24/tech-in-plain-sight-vacuum-blood-collection/)

Light blue: sodium citrate, which blocks clotting by binding calcium, reserved for coagulation tests. Red or gold: plain serum tube or gel separator. Green: heparin. Lavender: EDTA, hematology's anticoagulant, covering complete blood counts, HbA1c and lead assays. Gray: sodium fluoride, which halts glycolysis so glucose reads correctly. Yellow: SPS for blood cultures.[7](https://laboratories.newcastle-hospitals.nhs.uk/wp-content/uploads/2025/05/BD_order_of_draw.pdf)[8](https://www.ruh.nhs.uk/pathology/phlebotomy/documents/Phlebotomy_Order_of_Draw_Poster.pdf)

Each chemistry also dictates its own mixing protocol: three or four gentle inversions for citrate, five for serum tubes, eight to ten for heparin and EDTA. Mix poorly and the test runs again.[7](https://laboratories.newcastle-hospitals.nhs.uk/wp-content/uploads/2025/05/BD_order_of_draw.pdf)

> Illustration: Hand holding several filled evacuated blood tubes with different colored stoppers. The stopper color announces the additive inside the tube, and therefore the type of analysis possible. Credit: [Tom Mallinson (Tannim101), CC BY 3.0](https://commons.wikimedia.org/wiki/File:Vacutainer_blood_bottles.jpg).

## The order matters

That chemistry has a little-known consequence: the sequence in which tubes get filled is part of the standardized protocol, per the CLSI GP41 recommendation.[4](https://clsi.org/resources/insights-blog/order-of-blood-draw-tubes-and-additives/) Blood cultures first, then light-blue citrate, serum, green heparin, lavender EDTA, gray fluoride.

The reason is cross-contamination. Every tube carries a potent reagent, and carryover from one tube into the next skews measurements: a single drop of EDTA can fabricate a spurious potassium excess and calcium deficit, with a wrong medical decision potentially downstream. Work cited by the European federation of clinical chemistry shows contamination of roughly ten microliters, one droplet, is enough for some analytes.[5](https://www.eflm.eu/files/efcc/3.%20CCLM%202016%20WG-PRE.pdf)

One honest nuance: modern studies conclude this risk is nearly gone in today's closed system, where the additive sits lyophilized at the bottom of the tube and does not travel. The 2021 systematic review places contamination mostly on syringe-based draws, the open system.[6](https://pmc.ncbi.nlm.nih.gov/articles/PMC7915193/) But syringes never went away: an observational exercise in a UK emergency department found 52 percent of draws done by open-syringe method, with the EDTA tube filled first in 41 percent of cases.[5](https://www.eflm.eu/files/efcc/3.%20CCLM%202016%20WG-PRE.pdf) Hence the labs' pragmatic stance: keep one order everywhere rather than train two protocols.

Engineering even hides in the procedure details: when the draw goes through a butterfly set, air sits in the tubing. If a citrate tube must come first, you purge the line with a discard tube, otherwise dead volume skews the blood-to-additive ratio.[7](https://laboratories.newcastle-hospitals.nhs.uk/wp-content/uploads/2025/05/BD_order_of_draw.pdf)

## Invisible, but designed

None of this is visible from the patient's chair. The Vacutainer belongs to a family of objects where the entire design lives in invisible details: a metered vacuum, a sleeve that reseals itself, a color code shared worldwide, a fill order negotiated against the chemistry of reagents. Hackaday just ran it as its latest Tech in Plain Sight column, and the framing fits: the most ordinary technology is often the one that took the most years to engineer.[1](https://hackaday.com/2026/08/24/tech-in-plain-sight-vacuum-blood-collection/)

Next time you look away during the draw, look at the tube instead. The engineering is inside.

## References

1. [Zoe Skyforest, Tech In Plain Sight: Vacuum Blood Collection, Hackaday, August 24, 2026](https://hackaday.com/2026/08/24/tech-in-plain-sight-vacuum-blood-collection/)
2. [BD Newsroom, Celebrating 75 years of Evolution and Impact: BD Vacutainer Blood Collection Tubes, May 6, 2024](https://news.bd.com/Celebrating-75-years-of-Evolution-and-Impact-BD-Vacutainer-R-Blood-Collection-Tubes)
3. [Smithsonian National Museum of American History, B-D Vacutainer Combination Kit (collection object)](https://americanhistory.si.edu/collections/object/nmah_730875)
4. [CLSI, Order of Blood Draw Tubes and Additives, GP41, 2019](https://clsi.org/resources/insights-blog/order-of-blood-draw-tubes-and-additives/)
5. [Cornes et al., Order of blood draw: Opinion Paper by the EFLM Working Group for the Preanalytical Phase, Clinical Chemistry and Laboratory Medicine, 2016](https://www.eflm.eu/files/efcc/3.%20CCLM%202016%20WG-PRE.pdf)
6. [Doretti et al., The Order of Draw during Blood Collection: A Systematic Literature Review, IJERPH, 2021](https://pmc.ncbi.nlm.nih.gov/articles/PMC7915193/)
7. [BD, Tube guide and recommended order of draw for venous blood collection (PDF)](https://laboratories.newcastle-hospitals.nhs.uk/wp-content/uploads/2025/05/BD_order_of_draw.pdf)
8. [Royal United Hospitals Bath, Phlebotomy Order of Draw Poster (PDF)](https://www.ruh.nhs.uk/pathology/phlebotomy/documents/Phlebotomy_Order_of_Draw_Poster.pdf)
9. [United States Court of Appeals, Fifth Circuit, Becton Dickinson and Co. v. Sherwood Medical Industries, 516 F.2d 514 (1975)](https://law.resource.org/pub/us/case/reporter/F2/516/516.F2d.514.72-3599.html)