MEASURING MULTI-ANALYTE SAMPLES USING AN IN-LINE FLOW CELL

• US 20110189715A1
• Filed: 02/04/2010
• Published: 08/04/2011
• Est. Priority Date: 02/04/2010
• Status: Active Grant

• Current Assignee: Bio-Rad Laboratories Incorporated
• Original Assignee: Bio-Rad Laboratories Incorporated
• Inventors: Likuski, Robert K., Bartling, Don, Le, Tong, Prestigiacomo, Anthony F., Kramer, Kurt D.
• Granted Patent: US 8,790,592 B2
• Time in Patent Office: Days
• US Class Current: 435/29
• CPC Class Codes: G01N 1/28 Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Qmounting specimens on microscopic slides G02B21/34; means for supporting the objects or the materials to be analysed in electron microscopes H01J37/20 ; laboratory gas handling apparatus B01L5/00
• CPC Class Codes: G01N 15/06 Investigating concentration of particle suspensions by weighing G01N5/00; investigating sedimentation of particle suspensions G01N15/04; investigating individual particles G01N15/10
• CPC Class Codes: G01N 15/075 by optical means
• CPC Class Codes: G01N 2015/0693 by optical means, e.g. by integrated nephelometry
• CPC Class Codes: G01N 21/6486 Measuring fluorescence of biological material, e.g. DNA, RNA, cells G01N21/6428 takes precedence
• CPC Class Codes: G01N 30/06 Preparation
• CPC Class Codes: G01N 33/4915 using flow cells flow cytometry G01N15/14
• CPC Class Codes: G01N 35/00 Automatic analysis not limited to methods or materials provided for in any single one of groups G01N1/00 - G01N33/00; Handling materials therefor
• CPC Class Codes: G01N 35/1095 for supplying the samples to flow-through analysers for a specific analyser see relevant groups, e.g. under G01N15/00, G01N21/00, G01N27/00, G01N30/00, H01J49/00
• CPC Class Codes: G01N 35/1097 characterised by the valves valves in general F16K
• CPC Class Codes: Y10T 436/2575 Volumetric liquid transfer

Abstract

Methods and systems for analyzing ratios of analytes within a flowing sample are provided. The flowing sample can be processed in real-time to determine a time interval over which a predetermined amount of a group of analytes passes by a fixed point in a flow cell. The predetermined amount can be routed to a sample container for future processing. The sample can comprise diluted blood and the analytes can comprise a component of hemoglobin, such as A1c, and the total amount of hemoglobin, of which the predetermined amount is metered.

Claims

1. A method for measuring analytes in a sample, the method comprising:

flowing a sample containing analytes through a detector;

measuring a measurand of the analytes passing through the detector;

determining a time interval over which the measurand reaches a predetermined quantity; and

diverting a portion of the flowing sample containing the predetermined quantity of the measurand to a sample volume.

2. The method of claim 1, wherein the measurand has a linear relationship with analyte concentration.

3. The method of claim 2, wherein the measurand is based on light absorbance of analyte.

4. The method of claim 1, wherein measuring comprises performing a real-time integration of the measurand over the time interval.

5. The method of claim 4, wherein the time interval is pre-determined.

6. The method of claim 4, wherein the time interval starts at a first time point that is determined by a first measured threshold of the measurand.

7. The method of claim 6, wherein the sample is flowed into a waste output before the first time point.

8. The method of claim 7, wherein the first time point is the basis to switch at least one valve for diverting the portion of the flowing sample from the waste output to the sample volume.

9. The method of claim 4, wherein the time interval ends at a second time point that is determined by a second measured threshold of the measurand.

10. The method of claim 9, wherein the second threshold is determined by a calibration of a second threshold from a previous sample such that the second threshold is at or closer to a desired value.

11. The method of claim 1, wherein the sample comprises a blood dilution.

12. The method of claim 11, wherein the analyte of the blood dilution is a type of hemoglobin.

13. The method of claim 12, wherein the type of hemoglobin is one of A1c, labile A1, carbamylated A1c, E, D, S, or C.

14. The method of claim 1, wherein measuring a measurand of the analytes passing through the detector comprises determining an average amount of the analytes passing through the detector over the time interval to completely fill the sample volume.

15. The method of claim 14, further comprising:

determining a total amount of the analytes within the sample container from the average concentration.

16. The method of claim 14, further comprising:

injecting a portion of the sample container containing a desired amount of the analytes to a detector device.

17. A system for processing a sample, the system comprising:

a flow cell having an entrance and an exit;

a pump system fluidly coupled to the entrance of the flow cell, the pump system configured to move a sample into the flow cell;

a detector functionally attached to the flow cell;

a first transition valve fluidly coupled to the exit of the flow cell; and

a controller configured to determine when a fixed amount of a component of hemoglobin of a portion of the sample has flowed through the flow cell based on a signal from the detector, the controller being configured to switch the first transition valve in order to route the portion of the sample containing the fixed amount of the component of hemoglobin.

18. The system of claim 17, further comprising:

a waste unit fluidly coupled to the exit of the flow cell during a waste filling configuration; and

a sample volume fluidly coupled to the exit of the flow cell during a sample filling configuration,

wherein the controller is configured to switch the coupling of the first transition valve from the waste configuration to the sample filling configuration in order to route the sample from the waste unit to the sample volume.

19. The system of claim 18, wherein the controller is configured to switch the first transition valve to the sample filling configuration based on when a measurand of the component of hemoglobin reaches a first threshold.

20. The system of claim 19, wherein the controller is configured to switch the first transition valve from the sample filling configuration back to the waste filling configuration after the portion of the sample containing the fixed amount of the component of hemoglobin is flowed into the sample volume.

21. The system of claim 20, wherein the controller is configured to switch the first transition valve at a second time point based on a second threshold.

22. The system of claim 21, wherein the controller is configured to determine the second threshold by modifying a previous time threshold of a previous sample.

23. The method of claim 18, wherein the sample volume is a part of the injector of an HPLC system.

24. The method of claim 18, wherein the sample volume is a part of the reaction chamber for an immuno-assay system.

25. The system of claim 18, further comprising:

an injection valve fluidly coupled to the sample volume; and

a high pressure pump system fluidly coupled to the injection valve,

wherein the controller is configured to control the high pressure pump to send the portion of the sample containing the fixed amount of the component of hemoglobin in the sample volume to a separation and detection device.

26. The system of claim 17, further comprising:

a moveable needle arm functionally attached to a needle pump, the needle pump fluidly coupled to the flow cell,

wherein the controller is configured to control the needle arm and needle pump to supply fluid to the flow cell.

27. The system of claim 17, wherein the flow cell is configured to allow passage of light transversely to the sample flow direction of the flow cell.

28. The system of claim 27, wherein the detector comprises a light source and a photodiode positioned to receive light from the light source through the flow cell.

29. The system of claim 28, wherein the detector is an absorbance detector.

30. The system of claim 29, wherein the light source comprises an LED with peak output near 415 nm.