Patent ID: 8454903

Claim:
An assay device for detecting an analyte in a liquid sample, the assay device comprising: a casing, the casing comprising at least one window; a labeling region, the labeling region comprising a mobilisable labeled binding agent; and a nitrocellulose strip located within the casing, the nitrocellulose strip being substantially opaque in a dry state and being translucent when contacted by the liquid sample, the nitrocellulose strip comprising: (i) an analyte detection region comprising an immobilized binding agent which binds the analyte, the analyte detection region located downstream of the labeling region, wherein the analyte detection region is visible through the at least one window; (ii) a printed line located on the lower surface of the nitrocellulose strip in the analyte detection region, wherein the printed line is on the side of the nitrocellulose strip that is not visible through the at least one window when the nitrocellulose strip is in a dry state; (iii) a control region that is off-center from the flow path, the control region located downstream of the analyte detection region; wherein the control region is visible through the at least one window; and (iv) a sample presence indicator line, wherein said line is oriented substantially parallel with the direction of flow of the liquid sample; wherein in use, the liquid sample contacts and migrates along the nitrocellulose strip, and wherein the printed line is visible to a user through the at least one window when the nitrocellulose strip is translucent.