Every two seconds, someone in the United States needs a unit of blood. In this week’s 4 Your Health, we’re taking a closer look at how scientists are working to keep the blood supply safe and flowing.

The viles are loaded by the dozens. Blood samples run through the Prism,  an instrument designed by the healthcare company, Abbott, to screen for viruses and disease.

“Abbott tests are used to screen more than 60 percent of the world’s blood supply,” said John R Hackett Jr., an Abbott researcher.

The test specimens are kept in freezers and come from all over the world. Inside each box are 96 tubes, each filled with a blood sample that contains hepatitis or HIV. The specimens are used to run quality control tests to make sure the machines, which are in use at screening facilities around the world, are working properly to identify potentially harmful infections. But they also help scientists detect new threats.

“HIV and hepatitis viruses especially hep b and c evolve and change mutate very rapidly,” said Hackett.

Hackett is a virus hunter. He’s part of Abbott’s global surveillance program that looks for rare strains of known viruses, but also hopes to detect new ones well before they invade the blood supply.

“We’re advancing technology to actually be able to look for things that we may not even know are present in a sample, so new ways of analyzing specimens not only for infectious agents we’re aware of but to identify potentially new ones,” said Hackett.

Abbott created the first FDA-approved test to detect anti-bodies to human immunodeficiency virus or HIV back in 1985.

For more on Abbott, click here.