What Happens to Donated Blood?

After you donate blood, it goes through a complex system of testing, processing, and storage before it can be delivered to patients who need it. Learn how the system works in this episode of BrainStuff.

Learn more about your ad-choices at https://www.iheartpodcastnetwork.com

See omnystudio.com/listener for privacy information.

Episode Transcript

Speaker 1 (00:02):
Welcome to brain Stuff from How Stuff Works. Hey, brain Stuff,
Lauren Voga bomb here. This episode talks about blood donation.
So if that's the kind of thing that makes you woozy,
go on and skip it. Okay, Every two seconds in
the United States, someone somewhere needs a blood transfusion. And
let's face it, many of us don't consider giving blood

(00:23):
until there's a major disaster where donations are needed. But
just one donation has the potential to save up to
three lives on average. When you donate blood, you provide
about one pint. That's about half a leader of whole blood,
which is called a unit of blood, and for reference,
that's about sixteen ounces, or the size of a large coffee.
But in the U s alone, there is a need

(00:44):
for almost thirty six thousand units of blood every day,
so it's excellent for those who can donate to do so.
But have you ever wondered what actually happens after your
blood is drawn for a donation? Where does it go
and how is the process tracked for safety and security?
We'll break it down. Step one is collection. When you
donate blood, it's collected in a special bag and likely

(01:07):
a few test tubes that were developed with an antiquagulant
to prevent the blood from clotting. Each bag and test
tube is assigned the same unique I D number to
ensure that the collected blood can be properly tracked and
eventually labeled. Then the blood is placed on ice before
it's sent to the lab for testing. Next, the bags
and test tubes of blood are packaged in boxes specially

(01:28):
made to keep blood at the right temperature until it
can reach laboratories for step two processing, the test tube
samples are sent off to the lab for testing to
be sure the blood is safe and to determine the
blood type. In the US, the FDA regulates blood testing
collection and blood components through its Center for Biologics, Evaluation
and Research. While that blood is being tested, a blood

(01:49):
processing center verifies the receipt of the whole blood, sort
of like tracking a package from post office through delivery.
The blood's ideas checked in at every step of the way. Next,
the units of whole blood are separated into specific components.
This separation process, which is called component therapy, is accomplished
by spinning the blood in a centrifuge. The heavy red

(02:10):
cells fall to the bottom and the blood is divided
into transfusible components red cells, platelets, and plasma. The plasma
might even be processed further. For instance, plasma can be
separated into cryo precipitate called cryo for short, which helps
control the risk of bleeding by helping blood to clot.
The red blood cells, plasma, and platelets are then heat

(02:31):
sealed in bags to ensure they remain sterile, and the
components are stored while they wait for their test results.
Plasma and cryo contain proteins that are pretty stable, so
they can be frozen for up to a year at
negative twenty seven degrees fahrenheit that's negative thirty three celsius.
Red cells are more delicate and have to be refrigerated,
but can be kept for up to forty two days

(02:52):
as long as they're held at forty two degrees fahrenheit
that's six degrees celsius. Platelets must be used within five
days and are stored at room temper sure in agitators
that rock them back and forth until they are transfused
into a patient. Through all of this, the blood processing
center is still tracking the donation, including manufacturing data. What
centrifuge was used to separate the blood and what time

(03:13):
the work was performed. Once they get an okay on
the blood tests from the lab, the components are ready
to be deployed. They print labels with information including the
blood type and expiration dates, which they then affixed to
the bags. If the blood is deemed unsafe during the testing,
it's tagged with a discard label to complete the tracking cycle.
When a hospital or treatment center places in order for

(03:34):
blooder plasma, the components are shipped off in temperature safe boxes.
When they arrive, the medical staff double checks them for safety,
and finally they're ready to be transfused into the patient
who needs them. The entire donation to shipping process can
take up to three days, which doesn't seem like a
long time until there's a major disaster or blood shortage.

(03:54):
The American Red Cross says blood supply usually keep up
with demand because only about three percent of PEP eligible
to donate actually do. That's why it's such a boon
to donate if you can, especially if you're a universal
donor with type O negative blood. This can be transfused
into any patient with any blood type. The American Red
Cross estimates at about people in the us have Type

(04:16):
O blood, but the overwhelming majority of those people are
OH positive, which is lucky for them because it means
that donated components are more likely to match their common type,
but it also means that just seven percent of people
are Type O negative that universal donor. Today's episode was
written by Shelley Dancy and produced by Tyler Clang for

(04:38):
iHeart Media and How Stuff Works. For more on this
and lots of other topics, visit our home planet, how
stuff Works dot com