Patent ID: 8507259

Claim:
A test device for determining the presence of a ligand in a liquid sample, comprising: a) a first sorbent strip having a first location for receiving a solution and defining a first migration path; b) a second sorbent strip having a second location for receiving the liquid sample and defining a second migration path distinct from said first migration path, said second migration path including a conjugate of an antibody bound to an interim binding agent, said antibody being selected to bind to the ligand when present in the sample; c) a test site located on or in at least one of said first sorbent strip and said second sorbent strip, said test site having an immobilized binding agent, said interim binding agent and said immobilized binding agent chosen for their ability to selectively bind well to each other, said first and second sorbent strips touching each other at the test site location, and said second migration path extending laterally from said second location to at least said test site such that application of the liquid sample to the second location requires time for the liquid sample to laterally flow to the test site and does not immediately wet the test site upon application.