Flow through system, flow through device and a method of performing a test

1. A flow through system for quantifying a target component in a liquid, said flow through system comprising a flow-through device comprising a flow path comprising a marker section,

a capture section downstream to said marker section, and

at least two quantification sections,

said marker section comprises a non-immobilized marker,

said capture section comprises a capture zone with an immobilized capture agent, and

said at least two quantification sections comprise a pre-capture quantification section placed downstream to the marker section and upstream to the capture section, and a post-capture quantification section placed downstream to the capture section,

said quantification sections are in form of flow channel sections free of solid material selected from films or porous substrates, wherein said flow path in each of said quantification sections has at least one cross sectional dimension which is smaller than the corresponding cross sectional dimension in at least one, of said marker section and said capture section,

said system further comprise a quantification unit for each of said quantification sections, said quantification unit for each of said quantification sections being arranged to quantify marker containing components or particles passing through said respective quantification sections.

2. The flow through system as claimed in claim 1 wherein each quantification section comprises an optically transparent quantification window.

3. The flow through system as claimed in claim 1 wherein said marker section comprises at least one non-immobilized marker selected from marker particles, detectable particles colour markers, fluorescence markers, enzymes, antibodies, antigens, nucleic acids, metal particles or magnetic particles.

4. The flow through system as claimed in claim 1 wherein said capture zone is arranged in a pattern on at least one wall section of the flow path in said capture section.

5. The flow through system as claimed in claim 1 wherein said immobilized capture agent is immobilized in said capture zone, said immobilized capture agent being a specific binding partner to said target component.

6. The flow through system as claimed in claim 1 wherein said immobilized capture agent is selected from antibodies, antigens, polypeptides, enzymes or, nucleic acids.

7. The flow through system as claimed in claim 1 wherein said capture section also comprises a reference zone, said reference zone comprises an immobilized reference agent which is non-specific to said target component.

8. The flow through system as claimed in claim 7 wherein said immobilized reference agent is capable of binding to the marker.

9. The flow through system as claimed in claim 7 wherein said immobilized reference agent is selected from antibodies, antigens, polypeptides, enzymes or nucleic acids.

10. The flow through system as claimed in claim 1 wherein said flow path in each of said quantification sections has at least one cross sectional dimension which is less than 1000 μm.

11. The flow through system as claimed in claim 10 , wherein at least one quantification section comprises a transparent quantification window and wherein said cross sectional dimension is perpendicular to said quantification window or at least a part of said quantification window.

12. The flow through system as claimed in claim 1 wherein the capture section has a volume which is significantly larger than each of said quantification sections.

13. The flow through system as claimed in claim 1 wherein at least one of the capture section and the marker section comprises a substrate, selected from a porous or non-porous substrate.

14. The flow through system as claimed in claim 1 wherein at least one of the capture section and the marker section is essentially free of non-immobilized solid material.

15. The flow through system as claimed in claim 1 wherein the marker section has a volume which is significantly larger than each of said quantification sections.

16. The flow through system as claimed in claim 1 wherein the marker is arranged in said marker section in a distance from said pre-capture quantification section which distance is at least 1 mm.

17. The flow through system as claimed in claim 1 wherein the quantification units are wholly or partly placed in said quantification sections.

18. The flow through system as claimed in claim 1 wherein the quantification units are external units arranged in a detector instrument.

19. The flow through system as claimed in claim 1 wherein the quantification units are detector units detecting the amounts of particles or markers which pass through said respective quantification sections using electromagnetic waves, preferably selected from the group consisting of ultra violet light, infrared light, microwave radiation and visibly light.

20. The flow through system as claimed in claim 1 wherein the quantification units are optical sensors.

21. The flow through system as claimed in claim 1 wherein the flow through device further comprises a reference section arranged between the marker section and the post-capture quantification section, said flow through device further comprises a third quantification section (pre-reference quantification section) arranged between the marker section and said reference section.

22. The flow through system as claimed in claim 21 wherein said reference section not comprise any capture zone with immobilized capture agent, the reference section being essentially identical to the capture section except for the capture zone with immobilized capture agent.

23. The flow through system as claimed in claim 21 wherein said pre-reference quantification section is essentially identical to the pre-capture quantification section and the post-capture quantification section.

24. The flow through system as claimed in claim 21 wherein said system further comprises a quantification unit arranged to quantify marker containing components passing through said pre-reference quantification section.

25. The flow through system as claimed in claim 1 wherein said capture zone is arranged in a pattern on at least one wall section of the flow path in said capture section, the flow path in said capture section comprises a bottom wall and an opposite top wall, said capture zone being arranged on said bottom wall in said capture section, and said top wall in said capture section comprises a transparent display window above at least a part of said capture zone.

26. The flow through system as claimed in claim 1 wherein the quantification units are optical sensors selected from laser induced fluorescence detectors, fluorescence polarization detectors, fluorescence fluctuation detectors, particle counting sensors, concentration detection sensors, light absorption sensors, or light scattering sensors.

27. The flow through system as claimed in claim 1 wherein the quantification units are fluorescence polarization detectors, fluorescence fluctuation detectors, particle counting sensors, concentration detection sensors, light absorption sensors, or light scattering sensors.

28. The flow through system as claimed in claim 1 , wherein the flow path in said quantification sections comprises a bottom wall and an opposite top wall and a space between said bottom wall and said top wall, wherein said space being filled with gas prior to introducing said liquid.

29. A flow through device for quantifying a target component in a liquid, said flow through device comprising

a flow path comprising a marker section,

a capture section downstream to said marker section, and at least two quantification sections,

said marker section comprises a non-immobilized marker, said capture section comprises a capture zone with an immobilized capture agent, and

said at least two quantification sections comprise a pre-capture quantification section placed downstream to the marker section and upstream to the capture zone, said quantification sections are in form of flow channel sections free of solid material selected from films or porous substrates, wherein said flow path in each of said quantification sections has at least one cross sectional dimension which is smaller than the corresponding cross sectional dimension in at least one, of said marker section and said capture section,

a post-capture quantification section placed downstream to the capture zone and wherein said device further comprises a quantification unit for each of said quantification sections,

said quantification unit for each of said quantification sections being arranged to quantify marker containing components or particles passing through said respective quantification sections and being wholly or partly integrated with said flow through device.

30. The flow through device as claimed in claim 29 wherein the quantification units are wholly or partly placed in said quantification sections, the quantification units are detector units arranged to detecting amounts of particles or markers which pass through said respective quantification sections using electromagnetic waves.

31. The flow through device as claimed in claim 30 wherein the flow through device further comprises a reference section arranged between the marker section and the post-capture quantification section, said flow through device further comprises a third quantification section (pre-reference quantification section) arranged between the marker section and said reference section.

32. The flow through device as claimed in claim 31 wherein said pre-reference quantification section is essentially identical to the pre-capture quantification section and the post-capture quantification section.

33. The flow through device as claimed in claim 29 , wherein the flow path in said quantification sections comprises a bottom wall and an opposite top wall and a space between said bottom wall and said top wall, wherein said space being filled with gas prior to introducing said liquid.

34. A flow through system for quantifying a target component in a liquid, said flow through system comprising:

a flow-through device comprising a flow path comprising a marker section, said marker section comprises a non-immobilized marker for binding to the target component,

a capture section downstream to said marker section, said capture section comprises a capture zone with an immobilized capture agent for binding the non-immobilized marker bound to the target component,

a pre-capture quantification section placed downstream to the marker section and upstream to the capture section,

a post-capture quantification section placed downstream to the capture section,

said quantification sections are in form of flow channel sections free of solid material selected from films or porous substrates, wherein said flow path in each of said quantification sections has at least one cross sectional dimension which is smaller than the corresponding cross sectional dimension in at least one, of said marker section and said capture section,

a quantification unit for each of said quantification sections, said quantification unit for each of said quantification sections includes means for quantifying the marker containing components or particles passing through said respective quantification sections, said quantification units each generating a signal relating to a quantity of marker flowing through the respective quantification sections, and

means for comparing the signals from the quantification units for determining a value that reflects the amount of specifically captured target.

35. A method of determining the amount of target component in a liquid using a flow through system as defined in claim 1 , comprising

providing a flow-through device,

providing a sample of the liquid to be tested,

applying the liquid sample in an inlet to said flow path upstream to said marker section,

allowing said liquid sample to flow downstream to and preferably beyond the capture zone,

measuring a signal by each of the quantification units, and

based on the measured signals determining the amount or number of specifically captured target components based on a calibrated result.

36. The method of determining the amount of target component in a liquid as claimed in claim 35 , the method comprising measuring a signal by each of the quantification units in said pre-capture quantification section and said a post-capture quantification section, subtracting the signal from each other and determining the amount or number of specifically captured target components based on a calibrated result.

37. The method of determining the amount of target component in a liquid as claimed in claim 35 , the method comprising measuring a signal C 2 by the quantification unit in said pre-capture quantification section and measuring a signal C 3 by the quantification unit in said post-capture quantification section, and determining a capture signal X using the formula

( C 2 −C 3 )/ C 2 )= X,

and determining the amount or number of specifically captured target components represented by X based on a calibrated result.

38. The method of determining the amount of target component in a liquid as claimed in claim 35 , the method comprising measuring a signal C 1 by the quantification unit in said pre-reference quantification section, measuring a signal C 2 by the quantification unit in said pre-capture quantification section and measuring a signal C 3 by the quantification unit in said post-capture quantification section, and determining a capture signal Y using the formula

(( C 2 −C 3 )/ C 2 )/( C 1 /( C 1 −C 2 ))= Y,

and determining the amount or number of specifically captured target components represented by Y based on a calibrated result.

39. The method of determining the amount of target component in a liquid as claimed in claim 35 , wherein the quantification units are connected to or integrated with a detector instrument, said detector instrument comprises or is connected to a computer system arranged to perform calculation based on measurements obtained by the quantification units, the computer system being capable of calculating the difference between the signal obtained from the quantification unit in the post-capture quantification section and the quantification unit in the pre-capture quantification section, and compensating for non-specific binding by subtracting the result obtained by calculating the difference between the signal obtained from the quantification unit in the pre-capture quantification section and the quantification unit in the pre-reference quantification section, and determining the amount or number of specifically captured target components based on a calibrated result.