This invention provides solid phase specific binding lateral flow assay
methods, devices and kits for quantitating high and low molecular weight
analytes. The methods and devices of the invention employ labelled
reagents which are either analyte analogs or complementary specific
binding pair members for the analyte and a novel arrangement of capture
zones comprising immobilized specific binding substances for either the
analyte or the labelled reagent to effect bound from unbound labelled
reagent as a function of analyte concentration. The capture zones are
disposed on a non-bibulous matrix defining a flow path from a sample
receiving zone to the capture zone. The devices of this invention also
include multilane flow paths and multiple capture zones to quantitate
analyte.