Posted on 07/26/2020 2:31:18 PM PDT by Pining_4_TX
Saw online that the Red Cross will give free antibody test to those who donate blood. Seven to 10 day turnaround.
Note, however, that the test used is Ortho-Clinical Diagnostics (lgG), which has one of the lowest sensitivities (just 90%) but is 100% specific. That is, if you test positive, the result is extremely likely to be correct, but if you test negative, there is slight chance the test is wrong, i.e., antibodies are present but at levels below the test's threshold for detection, or the test did not recognize those antibodies.
I am ineligible to donate blood. Would if I could.
That’s fine. They can have my old DNA.
Ha, ha, I never go anywhere anyway. :-)
Well, guess it doesn’t matter. I spoke with a super-smart science guy and he said the antibody tests are pretty worthless. Oh well...
The info you shared from the Red Cross source are puzzling and concerning to me. At best, this analytical test would seems like quick and dirty screening test and as such would not be compatible with making a critical decision. Seems like a recipe for lots of false positives.
As examples.... “Sensitivity” is a term of not much utility. The common measure is “lower detection limit”, which is obtained via blanks and spikes within the analytical procedure and instruments. That 90% number thing might be referring to precision, which is a measure of repeatability. If so that’s pretty lousy for a quantitative test but may be acceptable for a qualitative test.
BTW, in analytical chemistry the is no such thing as zero. You will never see zero for any substance analyzed. What you will see is none detected greater than the lower detection limit. The lower detection limit is derived by using raw data from the sample analysis and quality control data from spikes and blanks. Statistics is a part of this determination as well.
I hope there is an analytical specialist that will comment on this better than I.
Blood is a biohazard material and goes into a biohazard waste container. The handing of the liquids and contaminated solids is highly regulated with detailed records documentation for inventory, management and disposal. Disposal is by incineration at a licensed facility. This is a thumbnail level overview that I think goes to your question.
My wife got one of them - I was hoping it would show antibodies so we’d know we both had it w/o problems, but it came back negative and now this article tells me we still don’t know.
Well, my son the scientist basically said the same thing. Looks like the test isn’t worth it.
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