Chromatographic test strip for determining ligands or receptors

A method for analysis of analyte in a sample by means of a sequential series of reactions, said method employing:

• a strip comprising a length of chromatographic material having capillarity and the capacity for chromatographic solvent transport of non-immobilized reagents and reactive sample components by means of a selected chromatographic solvent, said strip including,
• a first end at which chromatographic solvent transport begins;
• a second end, at which chromatographic solvent transport ends;
• a plurality of chromatographic solvent transport pathways;
• a plurality of zones positioned between said first and second ends, said zones including,
• a first zone impregnated with a first reagent which is mobile in said solvent and capable of a specific binding reaction with said analyte,
• a second zone for receiving said sample, and
• a third zone, downstream of said second zone, impregnated with a second reagent which is immobilized against solvent transport and is capable of a specific binding reaction with the analyte so as to immobilize the analyte in said third zone, said first and second zones being spaced sufficiently from said first end to permit contact of said first end but not said first and second zones with said chromatographic solvent, and
• means for directing said first reagent at said third zone,
• said method comprising:
• (1) disposing said sample in said second zone;
• (2) dipping said first end into chromatographic solvent for a time sufficient to chromatographically transport said analyte and said first reagent to said third zone, wherein the relative mobility of said sample components and said first reagent is controlled by said plurality of chromatographic solvent transport pathways such that the analyte is transported to and immobilized against solvent transport at the third zone prior to the first reagent reaching the third zone, and whereby interfering sample components and non-analyte components of the sample which are reactive with said first reagent are cleared from said third zone by the chromatographic solvent transport prior to the first reagent reaching said third zone;
• and (3) detecting the presence of said first reagent in said third zone as a measures of the analyte.

A method for analysis of analyte in a sample by means of a sequential series of reactions, said method employing:

• a strip comprising a length of chromatographic material having capillarity and the capacity for chromatographic solvent transport of non-immobilized reagents and reactive sample components by means of a selected chromatographic solvent, said strip including,
• a first end at which chromatographic solvent transport begins;
• a second end, at which chromatographic solvent transport ends;
• a plurality of zones positioned between said first and second ends, said zones including,
• a first zone impregnated with a first reagent which is mobile in said solvent and capable of a specific binding reaction with an analyte,
• a second zone for receiving said sample, and
• a third zone, coincident with said second zone, impregnated with a second reagent which is immobilized against solvent transport and is capable of a specific binding reaction with the analyte so as to immobilize the analyte in said third zone, said first and second zones being spaced sufficiently from said first end to permit contact of said first end but not said first and second zones with said chromatographic solvent, and
• means for detecting said first reagent at said third zone as a measure of the analyte,
• said method comprising:
• (1) disposing said sample in said second zone;
• (2) dipping said first end into said chromatographic solvent for a time sufficient to chromatographically transport said first reagent to said third zone, whereby after said first end is dipped into said chromatographic solvent, the relative mobility of said sample components and said first reagent is such that the analyte is immobilized against solvent transport at the third zone prior to the first reagent reaching the third zone, and whereby interfering sample components and non-analyte components of the sample which are reactive with said first reagent are cleared from said third zone by chromatographic solvent transport prior to the first reagent reaching said third zone, and (3) detecting the presence of said first reagent in said third zone as a measure of the analyte.