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Summary: If your worried about viruses in donated blood, learn how blood banks do the "bead test" as screening in this free video clip about the facts of blood donation.
Dr. Claudia Benekie is a research laboratory director of Stanford Blood Center.read more
"This bay is for Viral Marker testing. What we are doing here is determining whether a donor has an active infection, Hepatitis, HIV or HT; which is kind of like a leukemia or we're going to test to whether they have been exposed to any of those diseases. The test is a bead technology test so that means that the shape we are looking for, one of the shapes we are looking for is put on a little bead like so. This happens to be a test that's an anti-body test, so coated on this bead is an antigen; the actual virus itself, so those beads are going to be dropped into a tray. So the donor sample is going to be put into the source rack it's then going to be pipetted into a tray and notice everything here has a bar code. It's got a bar code here, there's a bar code on the source rack and there's a bar code on the actual donor sample. So the software is always going to link the donor sample to the tray and where it went into the actual tray. Once it has all been pipetted then, these beads that we talked about are going to be added in each one of the wells and then this tray is going to be incubated in an incubator, it's going to be incubated in an incubator so there is an incubation time. They'll then be taken out of the incubator it will be processed in this instrument here; it's called a Parallel Processing Center. Re-agents will be added to the tray and this particular test has three passes so we'll add a re-agent to it, incubate it. We take it out, we wash that out we put another re-agent into it, incubate it wash it out and put that last coloring re-agent that we talked about in the beginning. Then we're going to measure whether it's yellow or not. So if it's yellow, it's positive. If it's clear, it's negative. So the total throughput time for the older bead technology assay is about eight hours and we run, we do HIV and HTLV by beads."
eHow Article: Viral Marker Testing in Blood Donations