Apparatus and method for performing ligand binding assays on microarrays in multiwell plates

• US 8,039,270 B2
• Filed: 05/22/2008
• Issued: 10/18/2011
• Est. Priority Date: 05/22/2008
• Status: Active Grant

• Current Assignee: Maven Biotechnologies, LLC
• Original Assignee: Maven Technologies, LLC
• Inventors: Ralin, David, Dultz, Shane C
• Primary Examiner(s): CHIN, CHRISTOPHER L
• Application Number:
  US12/125,735
• Publication Number:
  US 20090290157A1
• Time in Patent Office: 1,244 Days
• Field of Search: None
• US Class Current: 436/518
• CPC Class Codes: G01N 2021/212 Arrangement with total internal reflection
• CPC Class Codes: G01N 21/211 Ellipsometry optical thickness measurement G01B11/06
• CPC Class Codes: G01N 21/253 for batch operation, i.e. multisample apparatus analytical automats G01N35/00
• CPC Class Codes: G01N 33/54373 involving physiochemical end-point determination, e.g. wave-guides, FETS, gratings
• CPC Class Codes: G02B 5/045 Prism arrays
• CPC Class Codes: Y10S 436/805 Optical property
• CPC Class Codes: Y10S 436/809 Multifield plates or multicontainer arrays

Abstract

Ellipsometry systems for imaging binding events between analytes in a sample and an array of ligands in an evanescent field generated by a beam of light reflected from the plane of the ligands is adapted to a multiwell plate structure in common use. In one example, a film of prism arrays is affixed to the underside of the plate with each prism array located in registry with a well and ligand arrays being immobilized on the (planar) bottom surface of the wells. The prism array may be formed in a film and juxtaposed with the bottom surface of the plate or a prism array can be made integral with the plate bottom of a multiwell plate.

Claims

1. An apparatus, comprising:

a plate having therein a plurality of wells, each of the wells having a planar bottom surface for receiving a sample for analysis, wherein the plate has a transparent planar underside; and

an array of prisms affixed to the underside, a plurality of prisms of the array being in registry with a corresponding one of the plurality of wells.

2. The apparatus as in claim 1, wherein the plurality of wells is arranged in rows and columns and wherein the array of prisms is formed as a continuous film.

3. The apparatus as in claim 2, wherein the continuous film comprises a layer integral with the underside of the plate.

4. The apparatus as in claim 1, wherein each prism of the array has a cross-sectional shape of a convex figure.

5. The apparatus of claim 4, wherein the convex figure includes a trapezoid.

6. The apparatus of claim 5, wherein a thickness t between the base of the plurality of prisms and the planar bottom surface of the corresponding one of the plurality of wells is given by

7. The apparatus as in claim 1, wherein the array of prisms includes a uniform pattern of prisms formed in a sheet of transparent material.

8. The apparatus as in claim 7, wherein the prism sheet has a corrugated surface on one side and a smooth surface on the other, wherein the corrugated surface includes a plurality of uniform linearly arrayed prism structures.

9. The apparatus as in claim 1, wherein the array of prisms is integral with the underside of the plate.

10. The apparatus as in claim 1, further comprising a top member against a top surface of a substrate, wherein the top member has an array of through apertures exposing portions of the top surface there.

11. The apparatus as in claim 10, wherein a plurality of ligand arrays are immobilized on the top surface of a substrate at an exposed portion.

12. The apparatus of claim 1, wherein a maximum height h of the plurality of prisms is given by

13. The apparatus of claim 1, wherein a distance x between adjacent prisms of the plurality of prisms is given by

14. A system, comprising:

a plate having therein a plurality of wells, each of the wells having a planar bottom surface including an array of immobilized ligands to receive a sample for analysis,

wherein the plate has a transparent planar underside, and an array of prisms affixed to the underside, a plurality of prisms of the array being in registry with a corresponding one of the plurality of wells and with an associated array of immobilized ligands; and

a source of a beam of light configured to direct the beam to a selected area of the array of immobilized ligands in a manner to achieve total internal reflection and to generate an evanescent field in the plane of the associated array of immobilized ligands.

15. The system as in claim 14, further comprising a sensor for sensing or measuring localized variations in the beam or beams reflected at the prisms.

16. The system as in claim 15, wherein the sensor senses or measures localized changes in intensity indicative of phase changes between the horizontal and vertical polarization vectors of a polarized beam of light responsive to the occurrence of binding between analytes in a sample in a well and ligands in an array.

17. The system as in claim 14, further comprising an optical system for directing the beam in a manner to achieve total internal reflection and to generate an evanescent field in the plane of the ligand array associated with a selected one of the prism array or position in the prism array.

18. The system as in claim 14, further comprising a sensor for sensing or measuring localized variations in the reflected beam.

19. The system as in claim 14, wherein the beam is a beam of polarized light.

20. A method of detecting binding events at an array of ligands immobilized on planar bottom surfaces of wells of a multiwell plate, the method comprising:

transmitting a beam of polarized light to a prism film affixed to an underside surface of the plate, the prism film including a plurality of prisms in registry with a corresponding one of the wells, the prism film being of a material and geometry to permit the beam of polarized light incident thereto to be totally internally reflected in a manner to generate an evanescent field in a plane of the array of ligands at which the beam is directed; and

obtaining an image of intensity variations in the reflected beam to detect binding events at said array of ligands.