×

Method for amplification of the response signal in a sandwich immunoassay

  • US 5,876,944 A
  • Filed: 06/10/1996
  • Issued: 03/02/1999
  • Est. Priority Date: 06/10/1996
  • Status: Expired due to Term
First Claim
Patent Images

1. In a sandwich type immunoassay in which there is immobilized to a first region of a strip of porous material through which a test fluid suspected of containing an analyte can flow by capillarity a first antibody which is specific for a first epitope of the analyte whose presence or concentration in a liquid test medium is being sought by applying the liquid test medium to the strip and in a second region of the strip there is contained a particulate label which is visible when bound to the strip without further treatment as primary signal generator which has directly bound to it multiple second antibodies which are specific to a second epitope of the analyte, the improvement which comprises including in the second region of the strip a secondary signal generator which is also a visible particulate label having attached to it multiple third antibodies which are specific for the second antibody attached to the primary signal generator but not specific for the parts of the second antibody which comprise the analyte binding sites which third antibody specifically binds to the second antibody to form signal amplifying complexes, and allowing the second labeled antibody and third labeled antibody to interact with each other and the analyte to form signal amplifying complexes to amplify the signal generated when the first immobilized antibody specifically binds with the first epitope of the analyte when the liquid test medium containing the signal amplifying complex of the second antibody, third antibody and analyte flow into the first region of the strip by capillarity to thereby bind the signal amplifying complex to the first region of the strip to thereby provide an amplified detectable signal in the first region of the strip.

View all claims
  • 2 Assignments
Timeline View
Assignment View
    ×
    ×