Optical detection system for particles

Patent metadata

Field	Value
Publication number	US-2017191924-A1
Application number	US-201615394605-A
Country	US
Kind code	A1
Filing date	Dec 29, 2016
Priority date	Dec 30, 2015
Publication date	Jul 6, 2017
Grant date	—

Abstract

Optical detection system and method for particles. In exemplary embodiments, the system may comprise a channel, a light source configured to generate light, and one or more optical elements configured to focus a beam of the light on an irradiation zone within the channel. The system also may comprise a mask operatively disposed in an optical path between the light source and the channel. The mask may be configured to block a portion of the beam, thereby producing a shadow region. The system further may comprise a detector configured to detect light deflected from the beam into the shadow region by interaction with a particle passing through the irradiation zone.

First claim

We claim:

1 . A detection system for particles, comprising:
a channel; a light source configured to generate light; one or more optical elements configured to focus a beam of the light on an irradiation zone within the channel; a mask operatively disposed in an optical path between the light source and the channel, wherein the mask is configured to block a portion of the beam, thereby producing a shadow region; and a detector configured to detect light deflected from the beam into the shadow region by interaction with a particle passing through the irradiation zone.

2 . The detection system of claim 1 , wherein the mask intersects a collimated region of the beam.

3 . The detection system of claim 1 , further comprising an optical slit operatively disposed in the optical path between the light source and the channel at a position optically upstream of the mask, wherein the mask is a line mask including a masking region elongated parallel to the optical slit, and wherein the masking region is elongated orthogonal to a flow direction in the channel through the irradiation zone.

4 . The detection system of claim 3 , wherein the optical slit is a first optical slit, further comprising a second optical slit operatively disposed in an optical path between the irradiation zone and the detector.

5 . The detection system of claim 1 , wherein the detector is a first detector, further comprising a second detector configured to detect photoluminescence induced by the beam in the irradiation zone, the one or more optical elements providing an objective that collects emitted light from the irradiation zone for propagation to the second detector.

6 . The detection system of claim 5 , wherein the same light source generates (i) light deflected by the particle at the irradiation zone and detected by the first detector, and (ii) excitation light that induces photoluminescence in the irradiation zone for detection by the second detector.

7 . The detection system of claim 1 , wherein the particle is selected from the group consisting of a droplet, a solid-phase particle, and a biological cell.

8 . The detection system of claim 1 , wherein the detector is configured to detect light near an image plane of the mask.

9 . The detection system of claim 1 , further comprising a source of carrier fluid containing particles of interest and disposed in fluid communication with the channel.

10 . The detection system of claim 9 , further comprising a source of dilution fluid in fluid communication with the channel and configured to increase a distance between particles in the channel at a position fluidically upstream of the irradiation zone by dilution of the carrier fluid containing particles of interest with the dilution fluid.

11 . The detection system of claim 1 , further comprising at least one source of positive/negative pressure operatively connected to the channel and configured to create a pressure differential that drives fluid flow through the channel.

12 . A detection system for particles, comprising:
a channel; a light source configured to generate light; an optical slit operatively disposed in an optical path between the light source and the channel; at least one collimating element operatively disposed in an optical path between the optical slit and the channel and configured to collimate the light to form a collimated beam; a line mask operatively disposed in an optical path between the collimating element and the channel, the line mask having an elongated masking region oriented parallel to the optical slit and being configured to produce a shadow region; one or more focusing elements operatively disposed in an optical path between the line mask and the channel and configured to focus the collimated beam on an irradiation zone within the channel; and a detector configured to detect light deflected from the collimated beam into the shadow region by a particle passing through the irradiation zone.

13 . A method of detecting a particle, the method comprising:
generating a beam of light; blocking a portion of the beam optically upstream of a channel to produce a shadow region; focusing the beam on an irradiation zone within the channel; passing a particle through the irradiation zone, wherein the step of passing deflects light into the shadow region by interaction with the particle; and detecting light in the shadow region.

14 . The method of claim 13 , wherein the step of blocking is performed on a collimated region of the beam.

15 . The method of claim 13 , wherein the step of blocking is performed with a mask, further comprising a step of passing light of the beam through an optical slit operatively disposed at a position optically upstream of the mask.

16 . The method of claim 13 , wherein the step of blocking includes a step of blocking a portion of the beam with a line mask having a masking region elongated orthogonal to the channel, and wherein the masking region is elongated parallel to an optical slit operatively disposed optically upstream of the line mask.

17 . The method of claim 13 , wherein the step of detecting is performed with a detector, further comprising a step of spatially filtering light of the beam with an optical slit disposed in an optical path between the channel and the detector.

18 . The method of claim 13 , further comprising a step of detecting photoluminescence induced by the beam at the irradiation zone.

19 . The method of claim 13 , wherein the step of passing a particle includes a step of passing a droplet through the irradiation zone.

20 . The method of claim 13 , wherein the step of blocking is performed with a mask, and wherein the step of detecting is performed behind an image plane of the mask.

21 . The method of claim 13 , wherein the step of detecting is performed with a detector, and wherein the light detected in the shadow region is not focused between the channel and the detector.

Assignees

• Bio Rad Laboratories Inc

Inventors

• Pristinski Denis

Classifications

• G01N15/1434 Primary

  Optical arrangements · CPC title

• G01N15/1404

  Handling flow, e.g. hydrodynamic focusing · CPC title

• G01N15/1459

  the analysis being performed on a sample stream · CPC title

• G01N2015/1409

  Physics · mapped topic

• G01N21/6428

  Measuring fluorescence of fluorescent products of reactions or of fluorochrome labelled reactive substances, e.g. measuring quenching effects, using measuring "optrodes" (in vivo A61B5/00; immunoassay G01N33/53) · CPC title