Here’s What Happens to Your Blood After You Donate It

Updated: Nov. 03, 2020

When you visit an American Red Cross site to donate, you're potentially saving at least three lives—but first, your blood must make a few surprising stops.

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It goes on ice

The initial needle-poke part of donating blood is easy and typically takes less than 15 minutes. But before your blood can be used by someone else, it takes some surprising twists and turns, starting with getting iced: The blood donation center staff places your collection bag in a cooler with the others until the donations can be taken for testing and processing; note that the staff will also set aside a tube of your blood for additional testing. They do this with every donor.

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At the Red Cross

Upon arrival at the Red Cross blood processing facility, the collection bags are unpacked and sorted based on the time the blood was donated. “The bags are separated by times, based on the type of product that will be manufactured (or separated into),” says Pampee Young, MD, PhD, chief medical officer of the American Red Cross Biomedical Division. The samples are sent for testing in a laboratory—the technicians are looking for viruses, bacteria, and other potential infections. (Find out why everyone should know their blood type.)

Doctor holding fresh donor blood for transfusion
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Blood is separated into three components

“Most whole blood donations are separated into transfusable components: red cells, platelets, and plasma,” says Dr. Young. Technicians use centrifuges to spin the blood at high speeds and separate the three components. “The testing and processing steps take approximately three days to complete,” says Dr. Young. Each of the three blood components can then be used to save up to three different people.

Blood donation
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Red blood cells go in the fridge

Once they’re separated out, red blood cells can be stored in a refrigerator for up to 42 days. “Patients who benefit most from transfusion of red blood cells include those with chronic anemia resulting from kidney failure or gastrointestinal bleeding, and patients with acute blood loss resulting from trauma,” says Dr. Young. “They can also be used to treat blood disorders such as sickle cell disease.” (Find out why blood is the color red.)

Bag of Platelets, donation of platelets

Plasma is frozen

Plasma is placed in a flash freezer, which is -27 degrees; it’s frozen solid in around 45 minutes. “Plasma is frozen within 24 hours of being donated giving it a shelf-life of one year,” says Dr. Young. “Plasma is commonly transfused to trauma, burn, and shock patients, as well as people with severe liver disease or multiple clotting factor deficiencies.”

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Platelets sit out on trays

As the plasma is freezing, the platelets are put on trays to sit undisturbed for at least one hour. The technicians place the platelets in a machine that gently moves back and forth to prevent bunching and clumping. “Platelets have a shelf-life of just five days,” says Dr. Young. “They are most often used during cancer treatment as well as surgical procedures such as organ transplant.”

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Sample tube analysis

While the three blood components from your blood undergo their various processing, your test-tube sample is being tested and screened for infectious diseases like hepatitis and HIV. Your blood will be kept separate until the test results reach the processing facility—usually within 24 hours. If you test positive for any infections, your donation is discarded and you’ll be informed of any infection. (Don’t miss what your blood type reveals about you.)

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The hospital is the next stop

When your donation gets the “all clear,” the Red Cross ships out the various blood products to hospitals all across the United States and U.S. territories, as well as the Mariana Islands, Marshall Islands, and the UN Mission Hospital in Haiti. “Hospitals determine their inventory needs based on the types of patients and their specific blood type and the required blood product (red blood cells, platelets, and plasma) needed for treatment,” says Dr. Young.

Close up on a donor blood bag in hospital ward

Your blood helps save someone’s life

Once your donation reaches a hospital, doctors must decide which patients have the most pressing need. According to the Red Cross, someone in the United States requires a blood transfusion every two seconds—that’s why it’s so crucial to donate if you’re able.  Each time you do donate, you have the potential to help keep three different people alive. Learn more about donating blood by visiting