Scanning fluorescent detection system
AssigneeE. I. Du Pont de Nemours and Company
InventorsCharles W. Robertson, Jr., Rudy J. Dam, James M. Prober
Life of this patent
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Abstract
A system for detecting the radiant energy emitted from different closely spaced species includes two detectors each having a large entrance angle for receiving the radiant energy, and wavelength selective filters between the detector and species, the transmission vs. wavelength characteristics being complementary, and means for ratioing functions of the detector outputs, the ratio being indicative of the identity of the species.
Claims26
In a system for detecting the presence of radiant energy emitted from different species, following separation in time and/or space, and the identity of such species, having first detection means responsive to the radiant energy emitted by the species for generating a first signal that varies in amplitude in a first sense as a function of the nature of the species, second detection means responsive to the radiant energy for generating a second signal that varies in amplitude in a second sense different than the first sense as a function of the nature of the species, and third means responsive to the first and second signals for obtaining a third signal corresponding to the ratio of functions of the first and second signals, the amplitude of the third signal being indicative of the identity of each of the species, the improvement wherein the first and second detection means each include:
- a detector having a large solid entrance angle positioned adjacent the species to receive radiant energy emitted from the species for generating one of the first and second signals,
- a wavelength selective filter means positioned between each respective detector and the species, each wavelength filter means having transmission vs. wavelength characteristics that are complementary, and
- wherein at least one of the first and second detection means includes a transmission filter means for rejecting radiant energy incident on the transmission filter means at an angle greater than a predetermined value.
A system as set forth in claim 19 wherein each transmission filter means has an extra mural absorber among plural optical fibers positioned to have parallel generatrices transverse to the first and second detection means.
Apparatus for detecting the presence of fluorescent radiation derived from fragments of DNA or other molecules labelled according to type with different fluorescing species of materials comprising:
- separation means adapted to spacially separate the molecules,
- means including a laser to sweep in a first plane a beam of radiant energy across the separation means to excite the species,
- first and second photodetectors having large solid entrance angle positioned on opposite sides of the first plane to convert fluorescent radiation emitted from the species into first and second signals,
- first and second wavelength filters having complementary transmission-wavelength characteristics interposed between the respective photodetectors and the separation means,
- a transmission filter, interposed between one of the respective photodetectors and its separation means, for rejecting radiation incidence on the photodetector at an angle greater than a predetermined value, and
- means responsive to the first and second signal for deriving a third signal corresponding to the ratio of functions of the first and second signals, the third signal being indicative of the identity of the fluorescing species.
Dependencies are inferred from the claim text.