Patent ID: 6528323
Filing Date: 2003-03-04
Classification: G01N,Y10S

Abstract:
A test strip adapted to receive a sample and detect an analyte therein, the test strip comprising:a sample addition zone to which a sample may be added; an absorbent zone positioned on the test strip in a first flow direction relative to the sample addition zone, wherein the absorbent zone comprises an absorbent pad that is affixed to the test strip; one or more test zones positioned on the test strip in a second, different flow direction relative to the sample addition zone, at least one of the test zones including a first analyte binding agent immobilized therein which is capable of binding to the analyte to be detected, the absorbent pad being in fluid communication with the sample addition zone and having an absorption capacity relative to the other zones of the test strip such that when a volume of sample within a predetermined sample volume range for the test strip is added to the sample addition zone, the sample initially diffuses from the sample addition zone both in the first flow direction to the absorbent zone and in the second flow direction past the one or more test zones and then reverses flow, and diffuses in the first flow direction past the one or more test zones toward the absorbent zone; and a conjugate buffer addition zone positioned on the test strip in the second flow direction relative to where the sample reverses flow, such that when conjugate buffer is added to the conjugate buffer addition zone, the conjugate buffer diffuses in the first flow direction past the one or more test zones.