A lateral flow assay device for detecting the presence or quantity of an
analyte within a test sample is provided. The device utilizes multiple
zones, one of which serves as an indicator of whether or not the analyte
in the test sample is within the "hook effect" region. Based on this
indication, a technique may be selected for correlating a measured signal
intensity to an analyte concentration or range of concentrations. For
example, when it is determined that the test sample falls outside the
"hook effect" region, the analyte concentration may be determined using
one portion of a dose response curve. On the other hand, when it is
determined that the test sample falls within the "hook effect"
concentration, the analyte concentration may be determined using another
portion of the dose response curve. Alternatively, the sample may simply
be diluted for re-performing the assay. The present inventor has
discovered that such a detection technique may simply, quickly and
accurately detect an analyte present at any concentration.