Abstract: Disclosed is a method for determining the presence and/or amount Oran analyte of interest in a liquid sample comprising the steps of: contacting the liquid sample suspected of containing analyte with a gas generating means (eg. catalase and peracid or peroxygen compound), which gas generating means forms a gas dependent upon the presence, absence or amount of analyte, which gas creates one or more bubbles in the liquid sample which act to alter the flow of liquid along a flow path; and determining an alteration of flow in the liquid wherein the alteration of flow of liquid along the flow path is indicative of the presence and/or amount of analyte in the liquid sample.

Abstract: Disclosed is an assay result reading apparatus, for reading the result of an assay, comprising: a) first and second control thresholds; b) a data processing means for processing an analyte measurement signal indicative of the presence and/or amount of an analyte; and for processing a control signal indicative of whether the assay has been carried out satisfactorily; to: up until a time t1 after commencement of the assay measurement, to compare the control signal with the first control threshold and determine that the assay has been carried out satisfactorily if the control signal exceeds or is equal to the first control threshold, and if the control signal is less than the first control threshold to continue the assay measurement; and at a time t>t1 to compare the control signal with a second control threshold and provide an assay result if the control signal exceeds or is equal to the second control threshold.

Abstract: Disclosed is an assay device for the determination of analyte in a liquid sample over an extended concentration range comprising a first assay and a second assay, wherein the first assay for an analyte comprises a first flow-path having a sole detection zone capable of immobilising a labelled binding reagent and the second assay for said analyte comprises a second flow-path having a sole detection zone capable of immobilising a labelled binding reagent, wherein the presence of labelled binding reagent at the detection zones provides an indication of the presence and/or extent of analyte in said liquid sample.