Deletion of Flow-through test

Comment: Bravo to M. A. Bruhn. There may be some ambiguity remaining in that non-clinical "flow-through assays" also exist (I added a MEDRS-compliant source discussing some), but that's a minor concern. Article as it stands approximately meets , with clinically relevant information cited to respected recent reviews
Stance: keep
Cited policy: Wikipedia:Reliable sources (WP:MEDRS)