ATLANTA -- Health officials on Saturday tested white particles found in donated blood to determine what they are and where they came from, although they weren't considered to be dangerous.
Testing was being handled by the Food and Drug Administration and the Centers for Disease Control and Prevention, said Mary Malarkey, director of case management for the FDA's Center for Biologics Evaluation and Research.
Hospitals in Georgia and north Florida were exercising caution with the blood they had Saturday.
At Northside Hospital in Atlanta, all surgeries with a major risk of blood loss were canceled, said spokeswoman Katherine Watson. Patients undergoing minor surgeries were asked to sign a consent form to make sure they were aware of the problem.
"We're fine right now as far as units for emergency cases," she said. "We're anticipating this will last at least until (Sunday) evening."
The particles set off an American Red Cross alert and canceled elective surgeries through the weekend. Hospitals were asked to suspend use of some of its blood, but the Red Cross reported that the particles are not infectious agents and that no harmful effects in patients have been reported.
Crawford Long and Emory hospitals in Atlanta reported short supplies of non-contaminated blood, said spokeswoman Debbie Bloom.
"Our supplies for this weekend are very limited," Bloom said. "But pending a major disaster, we'll be OK."
The problem was "likely with the bags" and not with the blood itself, said Chris Hrouda, the Red Cross' chief executive officer for blood services in the southern region. Only blood in bags manufactured by Baxter International Inc. had been found to be contaminated.
But a spokeswoman for Baxter said the particles were not related to the manufacturing of the bags. Baxter's test results may be ready by Monday.
"Both our tests and those of the Red Cross have indicated the particulate matter not to be an infectious agent," said spokeswoman Tanya Tyska. "It's biologic in nature, most likely blood-related."
The Red Cross reported that the particles are not infectious agents and that no harmful effects in patients have been reported. It has identified the location of all the possibly contaminated blood and was working with a maker of blood bags and the Food and Drug Administration to find out how the contamination happened.
The FBI said it was monitoring the case as a precaution, even though the initial investigation showed that the contamination was not sabotage.
The non-organic contaminant can be seen with the naked eye and is nearly translucent. The Red Cross said so far 110 of the approximately 4,000 units at its regional center were contaminated. The agency provides blood to 140 hospitals in Georgia and northern Florida, but it didn't know how much, if any, of its blood was affected.