Method for extending the range of an immunoassay
AssigneeDade Behring Inc.
InventorsTie Quan Wei, Thomas John Pankratz, Victor Pichai Chu
Life of this patent
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Abstract
Calibrating an immunoassay by generating two reaction rate measuring curves, from samples having higher and lower relative levels of antigen, extrapolating a combination of the curves to cover sample concentrations known to contain an excess of antigen relative to an amount of capture reagent and combining the low end linear potion of the higher reaction rate measuring curve with the higher end portion of the extrapolated reaction rate measuring curve, thereby eliminating measuring inaccuracies otherwise arising from the hook effect. For antigen concentrations higher than the assay range, a high antigen signal utilizing the two rates avoids reporting false results.
Claims14
A method for generating a calibration curve for an immunoassay comprising:
- separating a sample having an antigen concentration therein into a first larger volume portion and into a second smaller volume portion;
- generating first and second reaction rate curves each curve having a low end antigen concentration portion and a high end antigen concentration portion, the first reaction rate curve generated from the first larger volume portion and the second reaction rate curve generated from the second smaller volume portion;
- mathematically curve fitting the first and second curves in a low range of antigen concentrations for which both curves are linear;
- extrapolating the first reaction rate curve for those antigen concentrations containing an excess of antigen relative to an amount of capture reagent used in the immunoassay to produce an extrapolated reaction rate curve having a low end portion;
- combining the low end potion of the first reaction rate measuring curve with the higher end portion of the extrapolated reaction rate curve to produce a single curve;
- and,
- using the single curve as the calibration curve for an immunoassay thereby eliminating measuring inaccuracies otherwise arising from the hook effect.
Dependencies are inferred from the claim text.