What happens to blood after it’s donated? KSAT Explains

The Explains team takes you inside labs at the South Texas Blood & Tissue Center to show you how blood is ‘manufactured’

Full disclosure: I’m writing this KSAT Explains not only as journalist, but as a Champion.

Even fuller disclosure: I am not crazy about calling myself that.

But here’s why I did it: The South Texas Blood and Tissue Center (STBTC) asked me to be a Champion challenged to raise $10,000 for the life-saving organization.

So, Team Myra was born.


I’ve seen the need for blood in South Texas.

In Uvalde.

In Sutherland Springs.

In the stories of survivors, I’ve had the honor of meeting through my line of work.

What I haven’t seen — until now — is what happens to blood after it’s donated.

Where does it go? How is it stored? Tested? Processed?

This Champion effort gave me the opportunity to find out and take you along with me.

The money raised through this year’s Champion fundraising will go toward the purchase of new vehicles to transport blood donations.

If you have it in your heart and in your means to donate, thanks for considering it. It’s money that truly goes toward helping save someone’s life.

Donations are ‘manufactured’

When blood donations arrive at the South Texas Blood and Tissue Center, whether they’re collected at mobile blood drives or at the STBTC Donor Pavilion on site, the units are first brought to the Components and Manufacturing lab.

“We filter the unit and we also manufacture byproducts to include a plasma, a random donor platelet, a buffy coat. So there’s byproducts that are made within the donation we receive,” said Julian Salcido, Component Manufacturing Manager of the South Texas Blood and Tissue Center.

A buffy coat is the white layer between red blood cells and plasma and is a source of leukocytes often used in biomedical research, according to the National Institutes of Health.

Those products are separated from the whole blood donation in a centrifuge.

“There’s products that take 6 minutes. There’s products that take 4 minutes. There’s products like 9 minutes,” said Salcido.

Each product has a shelf life.

  • Blood: 42 days
  • Platelets: 5 days
  • Plasma: 1 year

After the centrifugation process, plasma is expressed using a machine that pushes the plasma into a separate bag by compressing the bag that contains the original donation.

Then an additive solution is drained into the blood donation to preserve it.

During that same process, white blood cells are removed using a small rectangular filter and then disposed.

“If those transfused to other patient, a recipient, that could attack your immune and you could have a reaction,” Salcido said.

How long does it last?

Each unit, which equates to one donation per person, produces three products:

1. Blood

2. Platelets

3. Plasma

Blood and platelets are refrigerated while plasma is frozen.

When asked how many units, on average, are sent to hospital systems each day Salcido replied, “not enough.”

“That’s a true statement,” he said. “It depends on our collections. It all depends on our demands of our local hospitals. There’s situations like we had in Uvalde in which we just.... We just depleted our inventory.”

In a matter hours, the supply was gone

On May 24, 2022, the day 19 children and two teachers were gunned down at Robb Elementary School in Uvalde, the South Texas Blood and Tissue Center supply was gone.

“I just don’t have the words, Myra,” Salcido said. “It’s hard. You know, it’s hard because some of us are parents. We regrouped, right? And in the end of the day, we just had to do what we had to do. End of story.”

“There are days in which we don’t know our target patients, because we really don’t,” he added. “But that day we knew.”

It’s emergencies like in Uvalde, Sutherland Springs, and countless other cities, for which STBTC must be prepared.

The South Texas Blood & Tissue Center serves 48 counties and more than 110 hospitals, which makes up about 22% of Texas.

The next step: testing

After blood donations are manufactured, a small sample is sent to a separate lab to test for viruses.

The QualTex Laboraties is located within the same building as the South Texas Blood & Tissue Center and owned by the same parent company, BioBridge Global.

QualTex tests the blood samples for an array of viruses, which takes 8 to 10 hours.

If viruses are detected, STBTC notifies the donor.

“When the blood is screened and it’s good to go, all of our results then are transferred. And then those results are communicated back through to South Texas,” said Vanessa Gallegos, Senior Operations Manager for QualTex. “And then South Texas follows their routine for providing those products to various places within the community.”

How will the money donated to Team Myra be used?

The South Texas Blood & Tissue Center says it will use the money donated through the Champion campaign to buy new vehicles to transport blood donations.

Those vans will replace the older models currently in use that do not have air conditioning in the back.

The blood is transported in coolers, but those coolers are sitting in temperatures that easily reach 130 degrees on a triple-digit day, according to Daniel De Leon, Customer Relations Coordinator for STBTC.

“A typical driver usually is on the road for a pretty close to 4 to 6 hours a day,” said De Leon. “We get to Laredo quite often, four times a week. We go down to the Valley at least once a day, and we go to Victoria a number of times.”

The vans are used to transport blood from donation sites and to hospitals throughout South Texas.

It’s so easy. A personal note...

. (KSAT)

Monetary donations are needed. The vans are needed. But blood is the crucial needed.

I hadn’t donated in years. At least before Covid and, even more likely, two pregnancies.

But I knew being a ‘Champion’ and covering this story was my opportunity.

STBTC says it takes about 45 minutes to an hour to donate. That’s probably true, but that’s not how long the actual process takes.

My ‘needle-in-arm’ time, if you will? 6 minutes and 32 seconds. (I learned the more hydrated you are, the faster it goes.)

It took me longer to fill out the questionnaire before we got started.

Click here to set up a donation time. There are locations all across the city.

About the Authors:

Myra Arthur is passionate about San Antonio and sharing its stories. She graduated high school in the Alamo City and always wanted to anchor and report in her hometown. Myra anchors KSAT News at 6:00 p.m. and hosts and reports for the streaming show, KSAT Explains. She joined KSAT in 2012 after anchoring and reporting in Waco and Corpus Christi.

Valerie Gomez is lead video editor and graphic artist for KSAT Explains. She began her career in 2014 and has been with KSAT since 2017. She helped create KSAT’s first digital-only newscast in 2018, and her work on KSAT Explains and various specials have earned her a Gracie Award from the Alliance for Women in Media and multiple Emmy nominations.