NORMALISATION METHOD AND NORMALISATION SYSTEM FOR A DRIED BLOOD MATRIX

Abstract

The present invention relates to a normalisation method for a dried blood matrix, said method comprising the steps: providing the dried blood matrix, extracting at least one analyte from a first portion of the dried blood matrix and haemoglobin from a second portion of the dried blood matrix, quantitatively analysing the at least one extracted analyte and the extracted haemoglobin, determining a concentration of the at least one analyte in the first portion of the dried blood matrix and a concentration of the haemoglobin in the second portion of the dried blood matrix, deriving the haematocrit of the second portion of the dried blood matrix on the basis of the concentration of the haemoglobin, and calculating a normalisation factor on the basis of the determined haematocrit in order to normalise the concentration of the at least one analyte in the first portion of the dried blood matrix. The invention also relates to a normalisation device (10) for performing a method according to the invention.

Claims

1. Normalisation method for a dried blood matrix, comprising the steps: providing the dried blood matrix, extracting at least one analyte from a first portion of the dried blood matrix and haemoglobin from a second portion of the dried blood matrix, quantitatively analysing the at least one extracted analyte and the extracted haemoglobin, determining a concentration of the at least one analyte in the first portion of the dried blood matrix and a concentration of the haemoglobin in the second portion of the dried blood matrix, deriving a haematocrit of the second portion of the dried blood matrix on the basis of the concentration of the haemoglobin, and calculating a normalisation factor on the basis of the determined haematocrit in order to normalise the concentration of the at least one analyte in the first portion of the dried blood matrix.

2. Normalisation method according to claim 1, characterised in that for the quantitative analysis of the haemoglobin, at least one peptide fragment of the haemoglobin is quantitatively analysed and a concentration of the at least one peptide fragment in the second portion of the dried blood matrix is then determined, wherein the concentration of the haemoglobin in the second portion of the dried blood matrix is concluded on the basis of the concentration of the at least one peptide fragment.

3. Normalisation method according to claim 1, characterised in that the quantitative analysis of the haemoglobin or of the at least one peptide fragment is carried out on the basis of a repeated selection of analyte-specific mass fragments generated in a mass spectrometer.

4. Normalisation method according to claim 1, characterised in that the quantitative analysis of the haemoglobin or of the at least one peptide fragment is carried out on the basis of analyte-specific mass-to-charge ratio signals, m/z.

5. Normalisation method according to claim 1, characterised in that for the quantitative analysis of the haemoglobin, the haemoglobin is enzymatically cleaved through the addition of a peptidase.

6. Normalisation method according to claim 1, characterised in that a plasma equivalent concentration of the at least one analyte is determined on the basis of the normalisation factor.

7. Normalisation method according to claim 1, characterised in that the at least one analyte is extracted from the dried blood matrix by means of an extraction liquid.

8. Normalisation method according to claim 1, characterised in that the at least one analyte is extracted from the dried blood matrix using an organic solvent.

9. Normalisation system (10) for a dried blood matrix, comprising an extraction unit (11) for extracting at least one analyte from a first portion of the dried blood matrix and haemoglobin from a second portion of the dried blood matrix, an analysis unit (12) for quantitatively analysing the at least one extracted analyte and the extracted haemoglobin, a determination unit (13) for determining a concentration of the at least one analyte in the first portion of the dried blood matrix and a concentration of the haemoglobin in the second portion of the dried blood matrix, a derivation unit (14) for deriving a haematocrit of the second portion of the dried blood matrix on the basis of the concentration of the haemoglobin, and a calculation unit (15) for calculating a normalisation factor on the basis of the determined haematocrit in order to normalise a concentration of the at least one analyte in the first portion of the dried blood matrix.

10. (canceled)

Description

[0038] In each case schematically:

[0039] FIG. 1 shows a flowchart explaining a preferred embodiment of the present invention, and

[0040] FIG. 2 shows a block diagram representing a normalisation system according to the invention.

[0041] FIG. 1 shows a block diagram explaining a normalisation method for a dried blood matrix. According to the embodiment shown, in a preparation step S1 a dried blood matrix is first provided, from which a first dried blood spot for the extraction of the analyte and a second dried blood spot for the extraction of haemoglobin are punched out.

[0042] In a second step S2, the analyte is extracted from the first dried blood spot by means of organic solvent and the haemoglobin is extracted from the second dried blood spot by means of an aqueous buffer.

[0043] In the context of measurements carried out in a third step S3, the extracted analyte and the extracted haemoglobin are then quantitatively analysed on the basis of a two-times selection of analyte-specific mass fragments generated in a mass spectrometer. That is to say, in each case an absolute amount of the respective substance is determined. For quantitative analysis of the haemoglobin, peptide fragments of the haemoglobin are quantitatively analysed and a concentration of the peptide fragments in the second dried blood spot is then determined, wherein the concentration of the haemoglobin in the second dried blood spot is concluded on the basis of the concentration of the peptide fragments. In addition, for the quantitative analysis of the haemoglobin the haemoglobin is enzymatically cleaved through the addition of a peptidase.

[0044] In a further step S4, the measured data or the analysis results are evaluated. In particular, a concentration of the at least one analyte in the first dried blood spot and a concentration of the haemoglobin in the second dried blood spot are determined.

[0045] In a subsequent fifth step S5, on the basis of the evaluation results the haematocrit of the second dried blood spots is derived on the basis of the determined haemoglobin concentration and a normalisation factor is calculated on the basis of the haematocrit in order to normalise the concentration of the analyte. During the translation, a plasma equivalent concentration of the at least one analyte is also determined on the basis of the normalisation factor.

[0046] FIG. 2 shows a normalisation system 10 for the dried blood matrix which is configured for carrying out a normalisation method as described above. The normalisation system 10 includes an extraction unit 11 for extracting at least one analyte from a first portion of the dried blood matrix or the first dried blood spot and haemoglobin from a second portion of the dried blood matrix or the second dried blood spot. The normalisation system also includes an analysis unit 12 for quantitatively analysing the at least one extracted analyte and the extracted haemoglobin and a determination unit 13 for determining a concentration of the at least one analyte in the first portion of the dried blood matrix and a concentration of the haemoglobin in the second portion of the dried blood matrix. In addition, the normalisation system includes a derivation unit 14 for deriving a haematocrit of the second portion of the dried blood matrix on the basis of the concentration of haemoglobin and a calculation unit 15 for calculating a normalisation factor on the basis of the determined haematocrit in order to normalise a concentration of the at least one analyte in the first portion of the dried blood matrix.

[0047] In addition to the embodiments illustrated, the invention allows for further design principles, i.e. the invention should not be considered to be limited to the embodiment illustrated in the Figures.

LIST OF REFERENCE SIGNS

[0048] 10 normalisation system [0049] 11 extraction unit [0050] 12 analysis unit [0051] 13 determination unit [0052] 14 derivation unit [0053] 15 calculation unit