Blood Cells for Sale

There's more to blood banking than just bagging blood

Join Our Community of Science Lovers!

On supporting science journalism

If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.

This is not a bag of blood. Granted, it did begin as a blood donation, drawn from the arm of a volunteer donor in Massachusetts. Within hours of collection, though, that precursory pint of warm whole blood had been centrifuged, fractionated and decanted into a red blood cell concentrate laced with a cocktail of chemical buffers and nutrients. The ruddy yield, shown here, is one chilled unit of processed blood product, suitable for a patient desperately in need of red cells. Such units—screened, packaged and tracked through their life cycles in keeping with the dictates of the U.S. Food and Drug Administration—are manufactured with assembly-line efficiency to optimize the safety and utility of a precious, limited resource.

A half-liter unit of whole blood, when spun, separates into layers. The 275-milliliter top layer of lemon-yellow plasma is rich in platelet cells, which are principal to blood clotting. The 225-ml bottom layer of red cells (erythrocytes), which shuttle oxygen and carbon dioxide around the body, is skimmed with a slick of the immune system’s white cells (leukocytes). Because different patients need varying boosts for different blood functions, packaging these layers separately lets each whole blood donation help several people. And reducing unnecessary biological material, such as the leukocytes in the red cell concentrate, lowers the risk that a patient’s immune system will reject a transfusion.

It’s Time to Stand Up for Science

If you enjoyed this article, I’d like to ask for your support. Scientific American has served as an advocate for science and industry for 180 years, and right now may be the most critical moment in that two-century history.

I’ve been a Scientific American subscriber since I was 12 years old, and it helped shape the way I look at the world. SciAm always educates and delights me, and inspires a sense of awe for our vast, beautiful universe. I hope it does that for you, too.

If you subscribe to Scientific American, you help ensure that our coverage is centered on meaningful research and discovery; that we have the resources to report on the decisions that threaten labs across the U.S.; and that we support both budding and working scientists at a time when the value of science itself too often goes unrecognized.

In return, you get essential news, captivating podcasts, brilliant infographics, can't-miss newsletters, must-watch videos, challenging games, and the science world's best writing and reporting. You can even gift someone a subscription.

There has never been a more important time for us to stand up and show why science matters. I hope you’ll support us in that mission.

Thank you,

David M. Ewalt, Editor in Chief, Scientific American