Pardon my ignorance, but the same thing can't be said for antibodies, can it?
Absolutely Not. Antibodies ARE most certainly in the blood. Its how they get about from where they are made to where they are needed. Antibody tests are eminently feasible.
IF DECN have an antibody assay (like 300+ others) they can slug it out with the 300+ others. They will be late to the party as others are already out and about, with no advantage over any of them.
But the whole 'impedance' smoke and mirrors - not a 'serology' test that was supposed to diffferentiate DECN assay and allow all these different virus detections and characterisations : THAT is a bad joke. I doubt they have it. And even if they did, it would not work. To use a poker analogy : They are holding '8' high, but representing a straight flush.
They've got nothing! Probably not even an antibody test!