Dried blood sample analysis

Abstract

A non-destructive method of estimating hematocrit (Hct) of whole blood from a dried blood sample prepared from the whole blood, the method comprising: a) determining the amount of hemoglobin derivatives comprising oxyhemoglobin, methemoglobin and hemichrome (total hemoglobin) in a dried blood sample, wherein the sum of the amounts of the hemoglobin derivatives remains constant in the dried blood sample in function of time, and b) estimating the hematocrit from the sum of the amounts of the hemoglobin derivatives, wherein the hematocrit is estimated using a calibration curve providing a correlation between hematocrit and the amount of the hemoglobin derivatives in a dried blood sample. The amount of the hemoglobin derivatives is preferably determined by measuring the reflectance, absorbance, or transmittance of the dried blood sample at the quasi-isosbestic point of the hemoglobin derivatives about 589 nm or at multiple wavelengths within the range of 450 to 750 nm.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a U.S. national stage entry under 35 U.S.C. § 371 of PCT International Patent Application No. PCT / EP2016 / 073741, filed Oct. 5, 2016, which claims priority to European Patent Application No. 15188354.3, filed Oct. 5, 2015, the contents of which are incorporated herein by reference in their entirety.FIELD OF THE INVENTION[0002]The present invention is situated in the field of blood sample analyte analysis, more particularly in the field of dried blood sample analysis and in methods for increasing the accuracy of quantitative analyte measurement in such samples by determining the hematocrit of such a sample.BACKGROUND OF THE INVENTION[0003]Dried blood samples are increasingly being used as an alternative for classical venous blood and plasma. In the analysis of dried blood samples, a major ‘unknown’, having an impact on the uncertainty of the analytical result, is the hematocrit (Hct), i.e. the volume percentage of red bl...

AI Technical Summary

Benefits of technology

The proposed method described in this patent is non-destructive, meaning it does not require manual punching or extraction, which saves time and reduces errors. It also maintains the integrity of the dried blood sample, allowing for further analysis. The use of a camera instead of an optical probe provides more information about the spatial distribution of hemoglobin within the sample. Additionally, a correction algorithm is provided to compensate for the Hct effect observed in dried blood sample analysis. Overall, this method is efficient, accurate, and adaptable for high-throughput environments.

Problems solved by technology

Furthermore, the proposed method is non-destructive and hence, excludes manual punching and extraction.

I.e. dried blood samples with low hematocrit values tend to yield an underestimation of the true analyte concentration in whole blood, whilst high hematocrit values tend to lead to overestimation.

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