The Three Laws of Food Pathogen Diagnostics

The 1st law

There is always a tradeoff between speed and sensitivity.

The probability of false negatives from any given rapid method increases proportionally with overall assay speed (i.e. reductions in assay enrichments, sample prep, and/or detection times).

Exactly what is the “proportion” and what is the “probability” may or may not be knowable but both will vary based on the specifics of the protocol in question and the overall time reduction.

The 2nd law

(For rapid molecular methods) volume of sample/enrichment transferred to detection is the ultimate driver of method sensitivity.

Increased volume = increased sensitivity

but also

Increased volume = increased probability of inhibition

and

Inhibition = decreased sensitivity

The 3rd law

Speed pays…usually.

People will (usually) pay more for faster methods (though never as much as you think), but they will not pay more for more sensitive methods unless required (even if they say they will).