Qualitative immunochromatographic method and device

A method for determining the presence at or above a predetermined minimum detectible amount of one or more of a plurality of analytes in a sample suspected of containing one or more of said analytes, which method comprises

• (a) contacting, with a test solution containing said sample and a predetermined amount of two or more analyte analogs each conjugated to an enzyme, the end portion of a strip of bibulous material capable of being traversed by said test solution by capillary migration, said strip having substantially uniformly and non-diffusively bound thereto predetermined amounts of two or more antibodies, each respectively capable of binding one of said analyte analogs and its corresponding analyte, such that in the presence of a predetermined amount of each analyte the corresponding analyte analog migrates at least to a predetermined site on said strip separated from said end portion,
• (b) allowing at least a portion of the test solution to traverse said strip past said predetermined site by capillary migration, and
• (c) examining said predetermined site for the presence of one or more of said analyte analogs, the presence thereof indicating the presence of one or more analytes in said sample.

A device for determining the presence at or above a predetermined minimum amount of one or more of a plurality of analytes in a test solution containing predetermined amounts of two or more first sbp members, each respectively analogous to one of said analytes, each analyte being a member of a specific binding pair, said device comprising

• a piece of bibulous material capable of traversal by said test solution in at least one direction by capillary migration, said bibulous material having a contact portion for contacting said test solution and a predetermined site separated from said contact portion and
• predetermined amounts of two or more second sbp members each respectively complementary to one of said analytes substantially uniformily and non-diffusively bound to said bibulous material at least between said contact portion and said predetermined site, said predetermined amounts of said second sbp members being such that in the presence at or above a predetermined minimum detectible amount of at least one of said analytes a first sbp member migrates to said predetermined site on said bibulous material and
• means associated with said bibulous material for allowing detection of one or more of said first sbp members only at said predetermined site, wherein said means is a signal inhibitor bound to said strip between said contact portion and said predetermined site.