Eastman-Kodak Company

Thomas A Weber

Paul A Kildal-Brandt

Charles E Heckler

A method of assaying analytes using a rate procedure is described where the change in density over time has a variable rate. The method features the steps of depositing the sample onto a dried slide-like test element, making an initial rate reading during an early time window, using the initial rate readings in a comparison study with rates from known low and high concentration results to predict whether the sample rate will be sufficiently low as to be ascertainable during a later time window or not, and then calculating a rate of reaction and concentration during either the early time window or the early time window with a portion of the later time window, respectively. To avoid the possibility of a consistent bias, the initial rate readings are used directly in the comparison study without first calculating a concentration, by comparing the initial rate reading of a sample against known rates corresponding to samples with low and high concentrations to determine the length of the time window to be used in the rate calculation.

Windowing in rate assays without using initial predicted concentration

There is described a method of calibrating an analyzer in the field, using parameters designed for a 'standard' analyzer that may be different from the field analyzer. In this way, it is not necessary to use only certain slide elements of a given chemistry on one analyzer, and certain other slide elements of that same chemistry on another analyzer. Instead, the slide elements are made interchangeable by calibration math which allow the field analyzer to convert its raw response R.sub.F into a response R.sub.standard of the selected 'standard' analyzer, using the equation

Normalizing analyzer systems to a standard analyzer

There is described a method of barcoding data needed to determine a calibration curve for a test element in an analyzer. The process follows the steps of: a) ascertaining by statistical analysis the ranges of values for R that are possible for three given concentration values C.sub.1, C.sub.2 and C.sub.3, for a given assay, and assigning a high value H and a low value L for these ranges; b) calculating for a given lot of the given assay, a calibration curve that correlates the analyzer response to the concentration, c) determining the analyzer response R.sub.1, R.sub.2 and R.sub.3 from said calibration curve, that corresponds to the C.sub.1, C.sub.2 and C.sub.3 values; d) calculating the bar code value B.sub.i for R.sub.i of each of these R.sub.1, R.sub.2 and R.sub.3 from the equation:

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Rochester, NY, United States of America

Thomas A Weber