Method, kit and system for imaging a blood sample

Patent metadata

Field	Value
Publication number	US-2016208306-A1
Application number	US-201615083610-A
Country	US
Kind code	A1
Filing date	Mar 29, 2016
Priority date	Jul 1, 2013
Publication date	Jul 21, 2016
Grant date	—

Abstract

Provided is a method for imaging a blood sample and a kit and system for executing the method. The method includes introducing a cell suspension including red blood cells onto a base surface of a carrier having a vertical height (H) being greater than or equal to a vertical depth (h) of the cell suspension when on the base carrier, the cell suspension including a cell concentration (C) being determined by a defined function; allowing the cells in the cell suspension to settle on the base surface of the carrier to form a monolayer of cells thereon; and acquiring at least one microscope image of at least a portion of the monolayer of cells; wherein the at least one microscope image is obtained by a microscope set to Depth Of Field that is not more than 20% of the vertical height of the cell suspension settled on the base surface.

First claim

1 - 51 . (canceled)

52 . A method for imaging a blood sample, the method comprising:
introducing a cell suspension comprising red blood cells, onto a base surface of a carrier; allowing the cells in the cell suspension to settle on the base surface of the carrier to form a monolayer of cells on the base surface of the carrier; and acquiring at least one microscope image of at least a portion of the monolayer of cells, the at least one microscope image being obtained by a microscope set to Depth Of Field (DOF) that is not more than 20% of a vertical depth of the cell suspension when settled on the base surface.

53 . The method of claim 52 , wherein the vertical depth of the cell suspension when settled on the base surface is between 20 μm and 1000 μm.

54 . The method of claim 52 , wherein the at least one microscope image is obtained by a microscope set to a DOF that is not more than 15% of the vertical depth of the cell suspension when settled on the base surface.

55 . The method of claim 53 , wherein the at least one microscope image is obtained by a microscope set to a DOF that is between 0.5 μm and 10 μm.

56 . The method of claim 52 , further comprising, prior to the introducing, diluting a blood sample comprising the cells by a dilution factor (D) to obtain the cell suspension.

57 . The method of claim 56 , wherein the factor D is between 50 and 300.

58 . The method of claim 52 , further comprising forming the cell suspension by diluting a blood sample comprising red blood cells to obtain a cell concentration such that, after the cell suspension settles on the base surface, the density of the cells of the cell suspension is between about 10,000 and about 30,000 cells per mm 2 .

59 . The method of claim 58 , wherein forming the cell suspension comprises forming the cell suspension such that after the cell suspension settles on the base surface, the cell suspension forms a monolayer having an average base surface coverage of between 40 percent and 90 percent.

60 . The method of claim 52 , further comprising selecting a microscope objective lens that provides the DOF, wherein the lens permits acquiring an image of at least one object being no more than 3 μm long at any dimension thereof.

61 . The method of claim 60 , wherein selecting the microscope objective lens comprises selecting a lens that permits acquiring an image of at least one object having a height with respect to the base surface of no more than 3 μm.

62 . The method of claim 52 , further comprising analyzing the at least one image to determine based thereon presence or absence of a pathogen in the cell suspension.

63 . The method of claim 62 , wherein at least part of the cells are infected with a blood infecting protozoa, and wherein analyzing the at least one image to determine based thereon presence or absence of a pathogen in the cell suspension comprises analyzing the at least one image to determine based thereon presence or absence of the blood infecting protozoa.

64 . The method of claim 63 , wherein the blood infecting protozoa is selected from the genus consisting of Trypanosoma, Plasmodium; Toxoplasma and Babesia.

65 . The method of claim 52 , wherein allowing the cells in the cell suspension to settle on the base surface of the carrier to form the monolayer of cells on the base surface of the carrier comprises allowing the cells to settle on the base surface for a period of time that is about 1 second per μm of vertical depth of the cell suspension when on the base surface.

66 . The method of claim 52 , wherein allowing the cells in the cell suspension to settle on the base surface of the carrier to form the monolayer of cells on the base surface of the carrier comprises allowing a period of time of less than 5 minutes for the cells to settle as a monolayer on the base surface.

67 . The method of claim 52 , wherein a vertical height of the carrier is between 20 μm and 300 μm.

68 . The method of claim 52 , wherein:
the cells are human cells comprising at least 75% red blood cells and at least part of the cells are infected with plasmodium selected from the group consisting of Plasmodium falciparum ( P. falciparum ), Plasmodium vivax ( P. vivax ), Plasmodium ovale ( P. ovale ), Plasmodium malariae ( P. malariae ), and Plasmodium knowlesi ( P. knowlesi ); the method comprises mixing the cells with one or more stains comprising at least one fluorescent stain before acquiring the at least one microscope image; and acquiring the at least one microscope image comprises acquiring a fluorescent image for detecting staining with the fluorescent stain.

69 . The method of claim 52 , wherein acquiring the at least one microscope image comprises acquiring a plurality of microscope images, at least two of which are provided under different conditions, the conditions comprising imaging different portions of the base surface and different illumination conditions.

70 . The method according to claim 52 , wherein introducing the cell suspension onto the base surface of the carrier comprises introducing the cell suspension onto the base surface of the carrier, the cell suspension having a concentration that is such that when substantially all of the cells in the cell suspension are allowed to settle on the base surface of the carrier to form the monolayer of cells, a monolayer is formed on the surface with substantially no overlap between the cells.

71 . A system for imaging a blood sample, the system comprising:
a blood sample preparing unit configured:
to receive a blood sample comprising red blood cells and at least one blood cell diluting agent, and
to form therefrom a blood cell suspension, that is such that the cell suspension forms a monolayer of the cells when allowed to settle on a base surface of a carrier;
a microscope image acquisition unit for acquiring at least one image of the blood cell suspension when on the base surface of the carrier; a controller being configured to acquire at least one microscope image of the cell suspension by a microscope set to a Depth Of Field (DOF) that is not more than 20% of a vertical depth of the cell suspension when settled on the base surface.

72 . The system of claim 71 , wherein the controller is configured to cause the microscope image acquisition unit to acquire a plurality of microscope images of the monolayer, at least two of which are provided under different conditions, the conditions comprising different portions of the monolayer and different illumination conditions.

73 . The system according to claim 71 , wherein the blood sample preparing unit is configured to form a blood cell suspension, that is such that that when substantially all of the cells in the cell suspension are allowed to settle on the base surface of the carrier to form the monolayer of cells, a monolayer is formed on the base surface with substantially no overlap between the cells.

Assignees

• S D Sight Diagnostics Ltd

Inventors

• Pollak Joseph Joel
• Houri Yafin Arnon
• Salpeter Seth J

Classifications

• G02B21/367

  providing an output produced by processing a plurality of individual source images, e.g. image tiling, montage, composite images, depth sectioning, image comparison · CPC title

• G02B21/34

  Microscope slides, e.g. mounting specimens on microscope slides · CPC title

• G02B21/0012

  Surgical microscopes (counterbalanced structures for surgical microscopes G02B7/001) · CPC title

• G02B21/16

  adapted for ultraviolet illumination {; Fluorescence microscopes (G02B21/0076 takes precedence)} · CPC title

• G01N21/6458

  Fluorescence microscopy (fluorescence microscopes per se G02B21/0076 and G02B21/16) · CPC title