Abstract: An assay device for determining an analyte in an aqueous sample comprises: (i) an elongate flow matrix (6) allowing lateral transport of fluid therethrough by capillary action, wherein the matrix comprises a liquid application zone (3) and downstream thereof, a detection zone (8) having an immobilized capture agent capable of directly or indirectly binding to said analyte, (ii) a wicking member (13) placed at the downstream end of the flow matrix and having an upstream end and a downstream end, and (iii) a time indicator (14) placed downstream of the detection zone (8) for indicating when liquid applied to the liquid application zone has reached the time indicator. The time indicator comprises an indicator substance or substance combination which is capable of exhibiting a visible color change when hydrated by the aqueous sample.

Abstract: An assay device for determining an analyte in an aqueous sample comprises: (i) an elongate flow matrix (6) allowing lateral transport of fluid therethrough by capillary action, wherein the matrix comprises a liquid application zone (3) and downstream thereof, a detection zone (8) having an immobilized capture agent capable of directly or indirectly binding to said analyte, (ii) a wicking member (13) placed at the downstream end of the flow matrix and having an upstream end and a downstream end, and (iii) a time indicator (14) placed downstream of the detection zone (8) for indicating when liquid applied to the liquid application zone has reached the time indicator. The time indicator comprises an indicator substance or substance combination which is capable of exhibiting a visible color change when hydrated by the aqueous sample.