Optics: measuring and testing – Sample – specimen – or standard holder or support – Fluid containers
Reexamination Certificate
1998-12-17
2001-04-03
Evans, F. L. (Department: 2877)
Optics: measuring and testing
Sample, specimen, or standard holder or support
Fluid containers
C250S458100
Reexamination Certificate
active
06211953
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a vessel for imaging fluorescent particles, and more particularly to a vessel for holding fluorescent particles such as leukocytes or the like stained with a fluorescent dye for imaging the fluorescent particles.
2. Description of the Prior Art
In the medical field, platelet preparations and erythrocyte preparations are produced by extracting platelets and erythrocytes from whole blood. These platelet and erythrocyte preparations are each used for blood transfusions, and it is undesirable for either preparation to contain leukocytes. It is therefore important to be able to know how many leukocytes the preparations contain. Conventionally this is done by placing a sample platelet preparation in a NAGEOTTE chamber, staining with a fluorescent dye, projecting an excitation light onto the sample and counting leukocytes via a microscope. Specifically, a 50 microliter sample is taken from a 200 or 400 milliliter bag of platelet preparation, the leukocytes in the sample are counted and converted to a leukocytes count for the whole bag. This is a tiring, inefficient, time-consuming task that has to be done by skilled personnel.
An apparatus has been proposed to enable leukocytes to be counted, instead, by staining the leukocytes with a fluorescent dye, illuminating the sample with an excitation light having predetermined wavelengths, using a CCD camera or the like to image the sample and then analyzing the images to obtain a count of the leukocytes. However, the solution containing the stained leukocytes also contains fluorescent dye that also emits fluorescent light. Thus, since not only the stained leukocytes but also the fluorescent dye itself is excited by the excitation light, there is a marked decrease in the contrast of the leukocytes that it is desired to observe or image. In some cases, the contrast may worsen to the point that the leukocyte images become so buried in the background that they cannot be picked out, making it impossible to count the leukocytes.
An object of the present invention is to provide a vessel for containing fluorescent particles that enables the fluorescent particles to be well imaged by reducing the effect of background light.
SUMMARY OF THE INVENTION
To attain the above object, the present invention provides a vessel for imaging fluorescent particles that are stained with fluorescent dye and illuminated by excitation light, the fluorescent particles being contained in a bottom portion of the vessel and imaged from below the bottom portion, wherein part of the exterior surface of the bottom portion is formed to be an excitation light entry surface.
In accordance with this arrangement, as the fluorescent particles that are the object of interest are accumulated in the bottom part of the imaging vessel and the bottom portion of the vessel has an external side face that is an entry surface for the excitation light, only the bottom portion of the vessel is illuminated by the excitation light, so background light can be reduced, thereby making it possible to obtain high-contrast images of the fluorescent particles in the vessel.
Background light can be further reduced by a considerable amount by using a shield member to cover parts of the imaging vessel other than the vicinity of the bottom portion.
It is preferable to form the bottom portion so that it has a square or rectangular horizontal cross-section with one side thereof forming an excitation light entry surface. The bottom portion may also be given a horizontal cross-section having a round shape, and a negative cylindrical lens disposed on the side from which the bottom portion is illuminated by the excitation beam.
Further features of the invention, its nature and various advantages will become more apparent from the accompanying drawings and following detailed description of the invention.
REFERENCES:
patent: Re. 32598 (1988-02-01), White
patent: 5225164 (1993-07-01), Astle
patent: 5355215 (1994-10-01), Schroeder et al.
patent: 5457527 (1995-10-01), Manns et al.
Komatsu Akio
Matsui Hiroki
Niino Masao
Adams & Wilks
Evans F. L.
Kowa Company Ltd.
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