I acquired two antibody lateral flow assays that purported to have the same sensitivity. I acquired NP antibodies and tested against them to validate they were not fake.
My testing protocol involved taking 0.1ul of antibody solution, and diluting it with PBS. One test succeeded up until a dilution of 1:200. One other test succeeded up until a dilution of 1:2500. Does this "threshold" mean anything? If it does, why do they show the same sensitivity levels? Did their samples that were cross-validated with RT-PCR just have high IgG / IgM levels?