Analytical assay
AssigneePB Diagnostic Systems, Inc.
InventorsJohn J. Blackwood, Shai Inbar
Life of this patent
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Abstract
A method for determining the amount of an analyte in a sample fluid utilizing an assay element which comprises at least one reagent layer. The assay method includes the steps of optically reading a signal producing species, e.g., a fluorescent label, a first time prior to depositing the sample fluid on the assay element and a second time, at the same wavelength and in the same location within the assay element after the sample fluid has been applied to the assay element and the sample analyte has interacted with the reagent(s) present in the assay element. The first, or dry, reading is corrected for relative humidity and/or temperature variations.
Claims17
A method for determining an analyte in a sample fluid consisting essentially of
- (a) irradiating a region of an assay element including a signal generating species with electromagnetic radiation to obtain a first optical signal prior to applying any sample fluid to said assay element;
- (b) correcting said first optical signal for relative humidity and/or temperature variations with an equation which utilizes temperature, relative humidity and time as variables to determine a basic dry reading, D.sub.o ;
- (c) applying a sample fluid to said assay element;
- (d) allowing analyte in said sample fluid to react with said signal generating species;
- (e) irradiating said assay element in the same region and with the same electromagnetic radiation utilized in step (a) to obtain a second optical reading;
- and
- (f) determining the amount of analyte in said sample fluid as a function of said basic dry reading and said second optical reading.
A method for processing a plurality of assay elements in an analytical instrument consisting essentially of
- (a) inserting a plurality of assay elements into a temperature controlled chamber of an analytical instrument;
- (b) irradiating at least one of said assay elements in a region thereof which includes a signal generating species with electromagnetic radiation to obtain a first optical signal for said assay element prior to applying any sample fluid to said element;
- (c) correcting said first optical signal for said assay element for relative humidity and/or temperature variations with an equation which utilizes temperature, relative humidity and time as variables to determine a basic dry reading, D.sub.o ;
- (d) applying sample fluid to said assay element;
- (e) allowing analyte in said sample fluid to react with said signal generating species;
- (f) irradiating said assay element in the same region and with the same electromagnetic radiation utilized in step (b) to obtain a second optical reading for said element;
- and
- (g) determining the amount of analyte in said sample fluid as a function of said basic dry reading and said second optical reading.
Dependencies are inferred from the claim text.