Patent ID: 7763433

Claim:
A method for the determination of a target analyte in a sample, said method comprising: a) applying a liquid sample suspected of containing said target analyte to a solid support capable of allowing lateral flow of liquid therethrough, which support has diffusibly arranged thereon, (i) either (a) a labelled binding partner for said analyte or (b) a labelled analogue of said analyte, and (ii) a labelled control reagent; b) allowing the sample, labelled binding partner for said analyte or a labelled analogue of said analyte and labelled control reagent to flow through a detection zone on said solid support, wherein in the case of (i)(a) above, a predetermined amount of an analogue of the target analyte is immobilised, or, in the case of (i)(b) above a predetermined amount of a binding partner for said analyte or labelled analogue is immobilised; c) allowing the sample, labelled binding partner for said analyte or a labelled analogue of said analyte and labelled control reagent to flow through a control zone on said solid support which is spaced from said detection zone, and in which a binding agent which binds the labelled control reagent is immobilised, said binding agent being present in an amount sufficient to give a similar signal to that which occurs in the detection zone when it is fully occupied by either the labelled binding partner for said analyte or the labelled analogue of said analyte, and d) detecting the label density in the detection zone (T), and the label density in the control zone (C) and comparing these densities.