Apparatus for performing fluorescent assays which separates bulk and evanescent fluorescence

• US 5,192,510 A
• Filed: 01/30/1991
• Issued: 03/09/1993
• Est. Priority Date: 01/30/1991
• Status: Expired due to Fees

• Current Assignee: Dade Behring, Inc. (Siemens AG)
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Craig, Alan R., Hochberg, Alan M., Davis, James E., Zoha, Steven J.
• Primary Examiner(s): Johnston, Jill A.
• Assistant Examiner(s): Soderquist, Arlen
• Application Number:
  US07/648,005
• Time in Patent Office: 769 Days
• Field of Search: 422/82.05-82.09, 422/82.11, 356/244, 356/246, 356/440, 250/277.31
• US Class Current: 422/82.05
• CPC Class Codes: G01N 2021/0364 flexible, compressible
• CPC Class Codes: G01N 21/648 using evanescent coupling or surface plasmon coupling for the excitation of fluorescence
• CPC Class Codes: G01N 33/585 with a particulate label, e.g. coloured latex
• CPC Class Codes: Y10S 435/968 High energy substrates, e.g. fluorescent, chemiluminescent, radioactive
• CPC Class Codes: Y10S 436/805 Optical property
• CPC Class Codes: Y10S 436/807 Apparatus included in process claim, e.g. physical support structures

Abstract

This invention uses the evanescent wave detection of particles to distinguish bound from free in an analyte-binding assay. Illumination below the critical angle is employed, and a beveled window is used to eliminate bulk fluorescence from the emitted evanescent wave liquid. The sample is held in a non-rigid film cuvette.

Claims

1. Apparatus for optically detecting an analyte of interest by separating bulk and evanescent emission from a tag capable of producing inelastic scattering of excitation radiation, comprising:

an optically transparent sample holder having an inner wall and holding a sample having the tag,

means for binding the tag to the inner wall immobilized on the inner wall, wherein at least a portion of the tag is bound to the inner wall in the presence of the analyte,

a prism connecting the sample holder contiguous the inner wall to provide an optical interface with the sample, the prism having an exit surface, and

means to excite the sample and tag to produce bulk emission and evanescent emission such that the bulk emission reaches the exit surface at an angle of incidence with the exit surface which is greater than the critical angle, whereby the bulk emission is totally internally reflected and the evanescent emission is passed through the exit surface.