Abstract: A method of measuring the rate of binding of a binding substance and an analyte, for example in an assay such as an immunoassay, uses an initial step of performing ultrasonication sufficient to disrupt binding between the binding substance and the analyte. After cessation of the ultrasonication, measurements are taken to determine the rate of binding at cessation of said ultrasonication or at a predetermined time thereafter. The ultrasonication results in knowledge of the precise time of the start of the binding reaction which provides a better rate measurement.

Abstract: A method of measuring the rate of binding of a binding substance and an analyte, for example in an assay such as an immunoassay, uses an initial step of performing ultrasonication sufficient to disrupt binding between the binding substance and the analyte. After cessation of the ultrasonication, measurements are taken to determine the rate of binding at cessation of said ultrasonication or at a predetermined time thereafter The ultrasonication results in knowledge of the precise time of the start of the binding reaction which provides a better rate measurement.

Abstract: The invention relates to a closure device and a method for performing an assay of a sample using the closure device. The closure device, mountable on the mouth of a test vessel, comprises a body part (1) with an axially passing cylindrical bore. The bore is covered at one end with an openable lid (7). The closure device further includes a plunger (3), slidably mounted in the bore for the formation of a sealed reagent storage chamber (9) in the space remaining between the closed lid and the plunger. The inner wall of the bore (2) is provided with at least one groove (4), whose depth is so deep as not to be within the reach of the outer diameter of the plunger (3). The groove extends from exterior end of the bore, over such a length as to maintain a gas flow communication between said reagent storage chamber (9) and the exterior end of the cylindrical bore when the plunger (3) is in a partially inserted position.