Patent ID: 7691595
Filing Date: 2010-04-06
Classification: G01N,Y10S

Abstract:
1. A method for quantitatively measuring the amount of an analyte of interest in a fluid sample, comprising: a) providing a solid phase apparatus comprising a membrane strip comprising an application point, a sample capture zone and a control capture zone, wherein the sample capture zone is between the application point and the control capture zone; b) providing a sample collection apparatus containing a population of analyte coated particles, wherein the analyte coated particles are coated with analyte or an analog of the analyte, and wherein the sample collection apparatus is not in fluid communication with the solid phase apparatus; c) either i) introducing the fluid sample into the sample collection apparatus, producing a mixed fluid sample, and subsequently introducing a buffer into the mixed fluid sample; ii) introducing a buffer into the sample collection apparatus and subsequently introducing the fluid sample; or iii) forming the fluid sample by introducing a solid into a buffer, and subsequently introducing the fluid sample into the sample collection apparatus,  thereby producing a buffered, mixed fluid sample comprising analyte coated particles; d) applying the buffered, mixed fluid sample to the application point of the membrane strip; e) maintaining the membrane strip under conditions which allow fluid to transport analyte coated particles by capillary action through the strip to and through the sample capture zone, the sample capture zone having a sample capture reagent immobilized thereon; and allow analyte coated particles to bind to the sample capture reagent; f) further maintaining the membrane strip under conditions which allow the fluid in the sample to transport analyte coated particles by capillary action through the strip to and through the control capture zone, the control capture zone having a control capture reagent immobilized thereon; and allow analyte coated particles to bind to the control capture reagent; g) further maintaining the membrane strip under conditions which allow the fluid in the sample to transport any analyte coated particles not bound to the sample capture reagent or to the control capture reagent by capillary action beyond the control capture zone; h) determining the amount of analyte coated particles in the sample capture zone and the amount of analyte coated particles in the control capture zone; i) determining a corrected analyte coated particle amount from the amount of analyte coated particles in the sample capture zone and the amount of analyte coated particles in the control capture zone,  wherein the amount of analyte of interest in the fluid sample is inversely related to the corrected analyte coated particle amount.