Assay for bilirubin
AssigneeEastman Kodak Company
InventorTai-Wing Wu
Life of this patent
Estimating the term…
Abstract
A method for the determination of bilirubin in liquid samples, particularly biological liquid samples. An assay method, as well as an analytical element, is disclosed. In accord with the assay method there are contacted together a liquid sample containing bilirubin as analyte and an interactive composition containing a bilirubin-active complex, the complex comprising a diffusible, bilirubin-displaceable, detectable ligand bound to a carrier which can also bind bilirubin. As a result of a competitive binding-displacement interaction between bilirubin and the complex, bilirubin binds to the carrier and displaces detectable ligand which can be selectively detected and used to determine the presence or amount of bilirubin. Appropriate carriers and detectable ligands can be chosen on the basis of their first order binding constants.
Claims33
A method for the detection of bilirubin in an aqueous liquid sample which comprises
- a. contacting together in a reagent zone said liquid sample and an interactive composition,
- such interactive composition containing a bilirubin-active complex comprising a diffusible, bilirubin-displaceable, detectable ligand bound to a carrier which can also bind bilirubin, said carrier having a first order binding constant to bilirubin in excess of 10.sup.7 and a first order binding constant to said detectable ligand which is in excess of 10.sup.5 but less than the aforementioned binding constant to bilirubin,
- whereby bilirubin displaces said detectable ligand from said interactive composition, and
- b. selectively detecting said detectable ligand.
An analytical element for the detection of a bilirubin in an aqueous liquid sample, said element comprising an initially dry reagent zone which comprises an interactive composition for the detection of bilirubin, such interactive composition containing a bilirubin-active complex comprising a diffusible, bilirubin-displaceable, detectable ligand bound to a carrier which can also bind bilirubin, said carrier having a first order binding constant to bilirubin in excess of 10.sup.7 and a first order binding constant to said detectable ligand which is in excess of 10.sup.5 but less than the aforementioned binding constant to bilirubin.
An analytical element for the detection of a bilirubin in an aqueous liquid sample, said element comprising an initially dry reagent zone and an initially dry spreading zone in fluid contact with one another under conditions of use,
- said reagent zone comprising an interactive composition for the detection of bilirubin, such interactive composition containing a bilirubin-active complex comprising a diffusible, bilirubin-displaceable, detectable ligand bound to a carrier which can also bind bilirubin, said carrier having a first order binding constant to bilirubin in excess of 10.sup.7 and a first order binding constant to said detectable ligand which is in excess of 10.sup.5 but less than the aforementioned binding constant to bilirubin, and
- said spreading zone comprising a porous polymeric composition or particulate matter.
An analytical element for the detection of a bilirubin in an aqueous liquid sample, said element comprising an initially dry reagent zone and an initially dry registration zone in fluid contact with one another under conditions of use,
- said reagent zone comprising an interactive composition for the detection of bilirubin, such interactive composition containing a bilirubin-active complex comprising a diffusible, bilirubin-displaceable, detectable ligand bound to a carrier which can also bind bilirubin, said carrier having a first order binding constant to bilirubin in excess of 10.sup.7 and a first order binding constant to said detectable ligand which is in excess of 10.sup.5 but less than the aforementioned binding constant to bilirubin, and
- said registration zone comprising material for receiving said diffusible ligand upon displacement thereof by bilirubin.
An analytical element for the detection of bilirubin in an aqueous liquid sample, said element comprising a reagent layer superposed on a registration layer carried on a radiation-transmissive support,
- said reagent layer comprising an interactive composition containing a bilirubin-active complex comprising a diffusible, bilirubin-displaceable, detectable ligand bound to a carrier which can also bind bilirubin, said carrier having a first order binding constant to bilirubin in excess of 10.sup.7 and a first order binding constant to said detectable ligand which is in excess of 10.sup.5 but less than the aforementioned binding constant to bilirubin, and
- said registration layer comprising a material for receiving said diffusible ligand upon displacement thereof by bilirubin.
An essentially dry multilayer analytical element for the detection of bilirubin in an aqueous liquid sample, said element comprising an isotropically porous spreading layer superposed over a reagent layer which, in turn, is superposed over a registration layer carried on a radiation-transmissive support, each of said layers in fluid contact with one another under conditions of use,
- said spreading layer comprising a porous polymeric composition or particulate matter and an amount of surfactant effective to normalize transport of bilirubin therethrough,
- said reagent layer comprising an interactive composition containing a bilirubin-active complex comprising a diffusible, bilirubin-displaceable, detectable ligand bound to a carrier which can also bind bilirubin, said carrier having a first order binding constant to bilirubin in excess of 10.sup.7 and a first order binding constant to said detectable ligand which is in excess of 10.sup.5 but less than the aforementioned binding constant to bilirubin, and
- said registration layer comprising a material for receiving said diffusible ligand upon displacement thereof by bilirubin.
Dependencies are inferred from the claim text.