(FORTUNE Small Business) – The American Association of Blood Banks estimates that about one in 5,000 units of blood platelets is infected with bacteria, which until recently could be passed to patients who receive transfusions. Infected blood can lead to serious complications and even death. (Platelets are given to cancer patients and people with clotting disorders.) In March the AABB started requiring all its member blood banks to test their platelets, but the tests typically took two to three days—a big delay, given that platelets, which are stored at room temperature, have a five-day shelf life. In response, GenPrime, a Spokane-based biotech company that specializes in bacteriological testing devices, will market its newest product, BacStat, to the blood industry starting in the spring.

BacStat is designed like a home pregnancy test: A researcher drips platelets onto it, and if a colored line appears within ten to 15 minutes, the blood is contaminated. BacStat registers positive only if there's a large enough concentration of contaminants.

"It's potentially useful to any market where there's a need to determine total bacteria or yeast count," says Jim Fleming, CEO of the 20-person company. That includes fluids in the food industry such as milk, water, and even beer. Fleming says that GenPrime will also target the beer industry, creating a version of BacStat that will help companies measure the bacteria content at various steps in the brewing process. —MAGGIE OVERFELT