This disclosure relates generally to a device for analysis of a target analyte, though more specifically, to a slide for isolating and/or processing the target analyte.
Suspensions often include materials of interest that are difficult to detect, extract and isolate for analysis. For instance, whole blood is a suspension of materials in a fluid. The materials include billions of red and white blood cells and platelets in a proteinaceous fluid called plasma. Whole blood is routinely examined for the presence of abnormal organisms or cells, such as fetal cells, endothelial cells, epithelial cells, parasites, bacteria, and inflammatory cells, and viruses, including HIV, cytomegalovirus, hepatitis C virus, and Epstein-Barr virus and nucleic acids. Currently, practitioners, researchers, and those working with blood samples try to separate, isolate, and extract certain components of a peripheral blood sample for examination. Typical techniques used to analyze a blood sample include the steps of smearing a film of blood on a slide and staining the film in a way that enables certain components to be examined by bright field microscopy.
On the other hand, materials of interest composed of particles that occur in very low numbers are especially difficult if not impossible to detect and analyze using many existing techniques. Consider, for instance, circulating tumor cells (“CTCs”), which are cancer cells that have detached from a tumor, circulate in the bloodstream, and may be regarded as seeds for subsequent growth of additional tumors (i.e., metastasis) in different tissues. The ability to accurately detect and analyze CTCs is of particular interest to oncologists and cancer researchers, but CTCs occur in very low numbers in peripheral whole blood samples. For instance, a 7.5 ml sample of peripheral whole blood that contains as few as 3 CTCs is considered clinically relevant in the diagnosis and treatment of a cancer patient. However, detecting even 1 CTC in a 7.5 ml blood sample may be clinically relevant and is equivalent to detecting 1 CTC in a background of about 50 billion red and white blood cells. Using existing techniques to find, isolate and extract as few as 3 CTCs of a whole blood sample is extremely time consuming, costly and is extremely difficult to accomplish.
As a result, practitioners, researchers, and those working with suspensions continue to seek systems and methods to more efficiently and accurately detect, isolate and extract target materials of a suspension.
This disclosure is directed to a slide for analyzing target analytes of a suspension. The slide can be used to collect and hold the target analyte for imaging or further processing. The slide comprises a well section, including wells into which the target analyte can be stored. The wells may be removable and sized to fit into a second apparatus, such as a PCR thermocycler, for additional processing. Alternatively, the wells may hold processing vessels, such as PCR tubes, the processing vessels being used for downstream processing and/or analysis.
As seen in
The wells can be cylindrical, spherical, conical, frustoconical, or any appropriate shape. A bottom or sidewall of the wells can include a plug 118 so that a target analyte can be held within the wells after the target analyte has been drawn into the wells. The plug 118 may then be removed, thereby dropping the target analyte into another vessel (not shown) which may be used for further processing, such as a PCR tube for PCR thermocycling. Alternatively, the plug 118 may be punctured by a removal device (not shown), such as a needle, to remove the target analyte from the wells so that the target analyte can be inserted into another vessel (not shown) for further processing. When the target analyte has been conjugated with a particle capable of being attracted by a magnetic field, a bottom end of the well section 116 may also include a magnet (not shown) so that the target analyte is attracted to and held within the wells.
The slide 500 also includes a well section 512 which includes wells 514. The well section 512 may extend upwards from the enclosure 504, may be co-planar with the enclosure 504, co-planar with the main body 502, or extend downward from the main body 502. The wells 514 may be straight or tapered and may hold a processing vessel (not shown), such as a PCR tube. At least one of the wells 514 may include a solution, such as phosphate buffered saline, water, mineral oil, DNA or RNA degraders (e.g. DNAZap™) to wash or purge a cannula of the cell picker or the pipette. The bottoms of the wells may be closed, such as with an optically clear material, an opaque material, or a plug, or may be open. The viewing station 508, the holding station 510, and the wells 514 permit imaging through the bottoms of the respective segments to ensure the presence of the target analyte and to ensure successful transfer of the target analyte from one segment to another. Alternatively, a slide 520 is similar to the slide 500, except that the viewing station 508, the holding station 510, and the well section 512 may extend through the main body 502, thereby starting at a top side of the main body 502 and ending at a bottom side of the main body 502, as shown in
The viewing station 508, the holding station 510, and the well section 512 may have the same focal plane, such that imaging from one station or section to the next does require refocusing. Alternatively, the viewing station 508 and the holding station 510, may have the same focal plane as one another, and the well section 512 includes a known offset such that the focal plane of the well section 512 is adjusted from the focal plane of the the viewing station 508 and the holding station 510 by the known offset.
The viewing station 508 holds a sample to allow for imaging of a sample and picking of a target analyte from the sample. The holding station 510 holds already picked target analytes prior to being deposited into processing vessels. The holding station 510 may include a solution to wash, dye, or process the target analyte. The holding station 510 may be one segment or may be a plurality of segments which are sectioned off by more than one divider, such that n dividers across the holding station yields n+1 segments within the holding station, where n is greater than or equal to 1 (i.e. one wall across the holding station 510 forms two segments; two walls across the holding station 510 forms three segments; etc.). Each target analyte may then be transferred, such as by a cell picker or a pipette, to a processing vessel (not shown), such as a PCR tube, that sits within the wells 514 of the well section 512. After the target analyte has been transferred to the processing vessel (not shown), the processing vessel (not shown) may be removed to perform further analysis and/or processing on the target analyte. Alternatively, the target analyte may be transferred directly to the processing vessel (not shown) from the viewing station 508.
The slide may allow for the use of a variety of magnification objectives, such as up to 100×, including 10×, 40×, 60×, and 63×. The target analyte may undergo subsequent processing and/or analysis which include techniques for sequencing, such as nucleic acid sequencing, polymerase chain reactions (“PCR”), extracellular analysis and/or intracellular protein analysis such as intracellular protein staining, in situ hybridization (“ISH”), or branched DNA (“bDNA”) analysis.
The slide or a portion thereof may permit for imaging, such that the slide is optically clear. Alternatively, the slide or a portion thereof may be opaque. The slide may be composed of glass, crystal, plastic, metal, or combinations thereof.
The slide may include a coating to reduce drag of the target analyte across the surface of the slide. Coatings may include, but are not limited to, plutonic, siliconizing reagent (e.g. Sigmacote®), or the like.
To collect the target analyte in a well, a suspension suspected of containing the target analyte or a fraction of a suspension suspected of containing the target analyte may be added to the main body section. The main body section may then be imaged to determine the presence and location of the target analyte.
Once collected, the target analyte may be analyzed using any appropriate analysis method or technique, though more specifically intracellular analysis including intracellular or extracellular protein labeling; nucleic acid analysis, including, but not limited to, protein or nucleic acid microarrays; FISH; or bDNA analysis. These techniques require isolation, permeabilization, and fixation of the target analyte prior to analysis. Some of the intracellular proteins which may be labeled include, but are not limited to, cytokeratin (“CK”), actin, Arp2/3, coronin, dystrophin, FtsZ, myosin, spectrin, tubulin, collagen, cathepsin D, ALDH, PBGD, Akt1, Akt2, c-myc, caspases, survivin, p27kip, FOXC2, BRAF, Phospho-Akt1 and 2, Phospho-Erk1/2, Erk1/2, P38 MAPK, Vimentin, ER, PgR, PI3K, pFAK, KRAS, ALKH1, Twist1, Snail1, ZEB1, Slug, Ki-67, M30, MAGEA3, phosphorylated receptor kinases, modified histones, chromatin-associated proteins, and MAGE. To fix, permeabilize, or label, fixing agents (such as formaldehyde, formalin, methanol, acetone, paraformaldehyde, or glutaraldehyde), detergents (such as saponin, polyoxyethylene, digitonin, octyl β-glucoside, octyl β-thioglucoside, 1-S-octyl-β-D-thioglucopyranoside, polysorbate-20, CHAPS, CHAPSO, (1,1,3,3-Tetramethylbutyl)phenyl-polyethylene glycol or octylphenol ethylene oxide), or labeling agents (such as fluorescently-labeled antibodies, Pap stain, Giemsa stain, or hematoxylin and eosin stain) may be used.
It should be understood that the method and system described and discussed herein may be used with any appropriate suspension or biological sample, such as blood, bone marrow, cystic fluid, ascites fluid, stool, semen, cerebrospinal fluid, nipple aspirate fluid, saliva, amniotic fluid, vaginal secretions, mucus membrane secretions, aqueous humor, vitreous humor, vomit, and any other physiological fluid or semi-solid. It should also be understood that a target analyte can be a cell, such as ova or a circulating tumor cell (“CTC”), a circulating endothelial cell, a vesicle, a liposome, a protein, a nucleic acid, a biological molecule, a naturally occurring or artificially prepared microscopic unit having an enclosed membrane, parasites, microorganisms, viruses, or inflammatory cells.
The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the disclosure. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the systems and methods described herein. The foregoing descriptions of specific embodiments are presented by way of examples for purposes of illustration and description. They are not intended to be exhaustive of or to limit this disclosure to the precise forms described. Many modifications and variations are possible in view of the above teachings. The embodiments are shown and described in order to best explain the principles of this disclosure and practical applications, to thereby enable others skilled in the art to best utilize this disclosure and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the scope of this disclosure be defined by the following claims and their equivalents:
This application claims the benefit of Provisional Application No. 61/804,280, filed Mar. 22, 2013.
Number | Date | Country | |
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61804280 | Mar 2013 | US |