U.S. patent application number 17/138503 was filed with the patent office on 2021-12-02 for whole blood separation sampling apparatus.
The applicant listed for this patent is Spot Bioscience, LLC. Invention is credited to James HILL, Jason WRIGHT.
Application Number | 20210372988 17/138503 |
Document ID | / |
Family ID | 1000005779546 |
Filed Date | 2021-12-02 |
United States Patent
Application |
20210372988 |
Kind Code |
A1 |
WRIGHT; Jason ; et
al. |
December 2, 2021 |
WHOLE BLOOD SEPARATION SAMPLING APPARATUS
Abstract
The present invention provides systems, devices, kits, and
methods for separating blood plasma or serum from whole blood. The
present invention further provides systems, devices, and methods
for separating a volume of blood plasm a or serum from whole
blood.
Inventors: |
WRIGHT; Jason; (Austin,
TX) ; HILL; James; (Manor, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Spot Bioscience, LLC |
San Francisco |
CA |
US |
|
|
Family ID: |
1000005779546 |
Appl. No.: |
17/138503 |
Filed: |
December 30, 2020 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
15104317 |
Jun 14, 2016 |
10883977 |
|
|
PCT/US14/71763 |
Dec 20, 2014 |
|
|
|
17138503 |
|
|
|
|
61919526 |
Dec 20, 2013 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G01N 2001/4088 20130101;
B01L 2300/0809 20130101; G01N 33/491 20130101; B01L 3/5023
20130101; B01L 2300/0681 20130101; B01L 2300/08 20130101; B01L
3/502 20130101; B01L 2300/0803 20130101; G01N 1/4077 20130101 |
International
Class: |
G01N 33/49 20060101
G01N033/49; B01L 3/00 20060101 B01L003/00; G01N 1/40 20060101
G01N001/40 |
Claims
1. A method of separating blood cells from whole blood comprising
the steps of: a) providing: i) a filter module, wherein said filter
module comprises a membrane configured to allow passage of blood
plasma or serum but not other blood components such as red blood
cells or white blood cells; and ii) a blood sample; b) applying
said blood sample to said membrane of said filter module; and c)
filtering said blood sample through said membrane using a lateral
flow.
2. The method of claim 1, wherein said filter module accommodates a
fixed volume of said blood sample.
3. The method of claim 1, wherein the filter module is a cartridge
having an interior chamber that houses the filter.
4. A device for separating plasma or serum from whole blood
comprising a filter module, wherein said filter module comprises a
filter configured to allow lateral passage of blood plasma or serum
but not other blood components such as red blood cells or white
blood cells.
5. The device of claim 4, wherein said filter module accommodates a
fixed volume of whole blood.
6. The device of claim 4, further comprising a drying agent within
the filter module.
7. The device of claim 6, wherein the drying agent is separated
from the filter by a mesh-like bather.
8. The device of claim 7, further comprising a barrier to calibrate
the rate of drying of the sample.
9. The device of claim 4, wherein the filter module is a cartridge
having an interior chamber that houses the filter.
10. The device of claim 4 wherein said filter is a spiral
membrane
11. The device of claim 4 wherein said filter is a circular-shape
membrane.
12. A method of separating blood cells from whole blood using the
device of claim 1.
Description
FIELD OF THE INVENTION
[0001] The present invention provides systems, devices, kits, and
methods for separating blood plasma or serum from whole blood. In
particular, the present invention provides systems, devices, and
methods for separating a volume of blood plasma or serum from whole
blood.
BACKGROUND OF THE INVENTION
[0002] Several up-stream processes are required before a complex
biological fluid can be analyzed for analytes. The separation of
plasma or serum is also a critical upstream process for the
detection and diagnosis of infectious diseases.
[0003] In a laboratory setting, the separation of plasma from whole
blood is carried out by centrifugation of blood for 20 minutes at
3000 g. In doing so, the solid components of blood settle down in
the sediment and the supernatant liquid consists of plasma. This
protocol usually requires a trained technician to manually pipette
out the supernatant for further analysis. While large scale
automated sample preparation systems can eliminate the manual step,
these instruments are expensive instrumentation, making them
unsuitable for resource limited or point-of-care testing.
[0004] Methods have been designed to integrate the centrifugal
blood separation with further downstream steps through a
micro-fluidic platform.
[0005] However, these methods work with an extremely limited volume
of whole blood, require the use of an instrument to create the
centrifugal force, are prone to clogging, and/or achieve only
limited purity. The use of synthetic membranes to separate blood
from plasma avoids some of the problems presented by centrifugation
and microfluidics systems; however, devices are complex due to the
need for multiple filtrations, and contain materials which retard
the flow of blood into the filters.
[0006] The present invention seeks to provide for a body fluid
collection and storage device as a dried sample providing for
increased sample stability/longevity and protection from
contamination or degradation.
[0007] The present invention provides systems, devices, kits, and
methods for separating blood plasma from whole blood. In
particular, the present invention provides systems, devices, and
methods for separating a volume (e.g., fixed volume) of blood
plasma or serum from blood cell component of whole blood.
[0008] Specifically, the claimed invention provides an apparatus
that allows blood collection, separation and drying as well as
storage in an enclosed cartridge, and uses a spiral membrane which
allows lateral flow blood separation in a round, spiral form.
SUMMARY OF THE INVENTION
[0009] The present invention provides a single-use apparatus for
blood collection and storage as a dried sample comprising
structural components that form an interior circular chamber(s)
containing a sample collection material(s), and a desiccant, the
sample collection material being in fluid communication with a
capillary tube or opening that extend to the exterior of the device
and through which the user introduces the fluid to be collected.
The all-in-one design of the device makes it ideally suited for
collection of blood samples in the field, where conventional sample
collection would be difficult.
[0010] An embodiment of the invention provides a device having a
spiral filtering membrane that allows lateral flow blood
separation. The spiral form of the membrane allows separation of
components of blood by virtue of the lateral flow.
[0011] In some embodiments, the present invention provides a method
of filtering blood plasma comprising: (a) providing: (i) a filter
module, wherein the filter module comprises a filter membrane
configured to allow lateral or horizontal flow; and (ii) a blood
sample; (b) applying the blood sample to the filter membrane of the
filter module; and (c) allowing the blood sample to flow laterally
or horizontally through the filter membrane. In some embodiments,
the filter module accommodates a fixed volume of blood sample.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 shows a spiral filter membrane in accordance with an
embodiment of the invention;
[0013] FIG. 2 shows a fluid collection device in accordance with an
embodiment of the invention;
[0014] FIG. 3A shows the use of the spiral filter in accordance
with an embodiment of the invention;
[0015] FIG. 3B shows the results of the use of a spiral filter in
accordance with an embodiment of the invention;
[0016] FIG. 4A shows the use of the spiral filter in accordance
with an embodiment of the invention;
[0017] FIGS. 4B to 4D shows the results of the use of a spiral
filter in accordance with an embodiment of the invention;
[0018] FIG. 5A shows the use of the spiral filter in accordance
with an embodiment of the invention; and
[0019] FIG. 5B shows the results of the use of a spiral filter in
accordance with an embodiment of the invention.
DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0020] The invention is directed to a fluid sampling device. In
certain embodiments, the fluid being sampled is blood. The device
contains one or more sampling materials suitable for collecting the
body fluid. Such sample collecting materials can include, as
non-limiting examples, filter paper or other solid support made
from materials including nylon, polypropylene, polyester, rayon,
cellulose, cellulose acetate, nitrocellulose, mixed cellulose
ester, glass microfiber filters, cotton, quartz microfiber,
polytetrafluoroethylene, polyvinylidene fluoride and the like. In
some preferred embodiments of the invention, the sample collecting
materials can be chemically treated to assist sample retention,
test preparation, or increase sample longevity, amongst other
things. Non-limiting examples include: to inactivate bacteria
and/or viruses; to denature proteins; to lyse cells, to inactivate
proteases, RNAses, DNAses and other enzymes, and/or to aid in
sample preparation. In some preferred embodiments, the sampling
material may be perforated or partitioned so as to provide the
sampler or tester with readily separable pieces of sampling
material.
[0021] In some embodiments of the invention, the collection
material is placed on a sample collection material such as a filter
having a spiral form.
[0022] In some preferred embodiments of the invention, the interior
of the device contain a drying agent or desiccant to remove
moisture from the sample. In further embodiments of the invention,
the drying agent or desiccant is separated from the filter by a
mesh-like barrier.
[0023] In certain embodiments, the interior of the device contains
a barrier to calibrate the rate of drying of the sample. The
barrier is made of materials such as filter paper, waxed paper,
plastics with small holes, and is placed between the mesh-like
bather and desiccant.
[0024] In some preferred embodiments of the present invention, the
device additionally comprises a lancet, needle, or other mechanism
to puncture the skin in order to provide access to the particular
body fluid.
[0025] In certain embodiments of the invention, the claimed device
provides a small footprint for easy handling. In further
embodiments of the invention, the device provides for fluid (whole
blood) separation from a small sample (2-6 drops) and drying and
storage for downstream testing. Additionally, the device displays
low hemolysis of the blood sample onto the spiral membrane.
[0026] The present invention provides systems, devices, kits, and
methods for separating blood plasma or serum from whole blood. In
particular, the present invention provides systems, devices, and
methods for separating a volume (e.g., fixed volume) of blood
plasma or serum from whole blood. In some embodiments, the present
invention provides systems and devices for separating blood plasma
or serum from whole blood. In some embodiments, devices separate
blood plasma or serum from other blood components (e.g., blood
cells). In some embodiments, the present invention provides a
filter element. In some embodiments, whole blood (e.g., unfiltered)
is added to a filter element, and the blood is filtered (e.g., by
capillary action, by gravity, etc.) through the filter element
using lateral flow. In some embodiments of the device, certain
analytes might be added to the filter element as an internal
standard.
[0027] An embodiment of the invention is directed to a method of
filtering blood plasma or serum comprising: a) providing: i) a
filter module, wherein said filter module comprises a filter
configured to allow passage of blood plasma or serum but not other
blood components; and ii) a blood sample; b) applying said blood
sample to said filter of said filter module; and c) filtering said
blood plasma or serum through said filter.
[0028] Another embodiment of the invention is directed to a device
for separating plasma or serum from whole blood comprising a) a
filter module, wherein said filter module comprises a filter
configured to allow passage of blood plasma or serum but not other
blood components.
[0029] In some embodiments, the present invention provides a filter
element. In some embodiments, one or more blood components (e.g.,
cellular components) move more slowly through the filter element
than blood plasma.
[0030] In some embodiments, blood components other than plasma
(e.g., cellular components) are unable to move through the filter
element. In some embodiments, blood plasma rapidly (e.g., more
rapidly than other blood components) advances through the filter
element. In some embodiments, the filter element comprises a filter
capable of separating blood plasma from other blood components
based on capillarity. In some embodiments, the filter is a spiral
membrane. In certain embodiments, the filter is a circular
membrane. A spiral-shaped membrane is shown in accordance with an
embodiment of the invention is shown in FIG. 1.
[0031] The advantages/benefits for using a spiral membrane include
a small footprint that fits into a cartridge (easy handling).
Additionally a spiral membrane allows fluid (whole blood)
separation from a small sample (2-6 drops) and drying and storage
for downstream testing. Furthermore, the use of a spiral membrane
reduces the level of hemolysis of the sample blood during movement
on to the membrane by virtue of the use of lateral movement of the
sample on to the membrane.
[0032] The device of the present invention presents
advantages/benefits compared to the existing blood separation
devices. These advantages include separating cells such as red
blood cells and white blood cells from whole blood; use of a drying
agent (desiccant) separated from the sampling membrane by plastic
mesh with air holes allowing rapid drying; and the ability to
calibrate drying rate and thus control resulting sample area.
[0033] As set forth in FIG. 2, the device of the claimed invention
100 comprises several components. A moisture-tight cartridge 110 is
provided. Inside the cartridge 110, the applicator 120, sampling
membrane 130, mesh barrier 140 and desiccant 150 are arranged as
shown in FIG. 2. The mesh barrier 140 is arranged between the
desiccant 150 and the sampling membrane 130 to prevent contact
between the desiccant and the sampling membrane while still
furthering the drying process. In certain embodiments, an
additional barrier 160 is inserted between the mesh barrier 140 and
the desiccant 150. The barrier 160 calibrates the rate of drying of
the sample and provides an accurate reading of the component being
measured.
WORKING EXAMPLES
[0034] Multiple designs were examined in an attempt to identify an
ideal form that could take advantage of the existing HemaSpot
platform, while providing enough surface area and length to allow
the plasma/serum to separate from red blood cells, while also
remaining concentrated enough to allow easy isolation of sufficient
material for analytical work. While a straight line for the blood
to wick down is the most obvious design for the separation process,
a straight line would not fit into the HemaSpot platform while a
circular design would be compact and fit well.
[0035] After a number of design trials were investigated, all
designed to fit under the HemaSpot applicator and above the
HemaSpot desiccant, a final spiral design was identified that could
provide the area needed for up to 150 .mu.L of whole blood and the
length required to allow separation of the plasma or serum
component from the whole blood.
[0036] Trials were performed to identify the area of the material
the red blood cells would occupy. With addition of 50, 75 and 100
.mu.L of whole blood (WB), the average red blood cell (RBC) area
was found to be 4.0 mm.sup.-2/.mu.L WB. For an estimated 80 to 100
.mu.L of WB from a finger stick, the area occupied by RBC's would
be between 320 and 400 mm.sup.-2.
[0037] To this end, spiral forms were crafted (see FIGS. 1 & 2)
with a center portion ranging from approximately 12-14 mm diameter,
comprising up to 154 mm.sup.-2 area. This area is enough to hold
the RBC's from 40 .mu.L of WB with an average hematocrit (HCT).
With the spiral arm being approximately 8 mm in width around the
center, RBC's would be expected to move only a quarter of the
circumference around the spiral. Plasma or serum would occupy the
remainder of the spiral arm.
[0038] In an experimental trial, a blood sample was placed on a
spiral membrane at a location "0" as set forth in FIG. 3A. 4 mm
punches were taken from the plasma portion around the spiral to
analyze for any chromatographic effect the filter material might
have on total protein. A picture of this arrangement is provided in
FIG. 3A. The results of the protein analysis of each of the four
punches from two trials are provided in FIG. 3B. From FIG. 3B, a
chromatographic effect of total protein can be seen as the punch
location moves away from the red blood cell front. The farther the
location of the punch sample, the greater the protein concentration
due to the presence of increasing amounts of plasma and serum at
locations on the filter farther away from the sampling site. Thus,
there is a greater amount of protein at a distance of 16 mm from
the sampling site than at 8 mm.
[0039] As shown in FIGS. 4A to 4C, fresh whole human blood was
applied to the spiral form and dried. Punches were removed as
indicated (FIG. 4A) and extracted. DNA was isolated using DNAzol
standard methods and measured by Pico Green fluorescence (FIG. 4B).
RNA was isolated by Trizol methods and analyzed by absorbance at
260 and 280 nm (FIG. 4C). A small molecule, nifedipine, was
analyzed by LC-MS/MS methods (FIG. 4D). As shown in FIG. 4B, the
greatest concentration of DNA is located at the site where the
sample is introduced onto the filter. Similarly, the concentration
of RNA is greatest at the site where the sample is introduced onto
the filter. The RNA and DNA concentrations dramatically decrease as
the distance of the punch location increases from the sampling
site.
[0040] Fresh whole human blood was applied to spiral membrane and
dried (FIG. 5A). Punches were removed as indicated (FIG. 5A) and
extracted. Homocysteine levels were measured by LC-MS/MS methods
(FIG. 5B). As seen in FIG. 5B, there is a greater amount of
homocysteine at a punch location 4, i.e., the location that is
farthest from the sampling site than at punch location 1, i.e., the
location that is closest to the sampling site. This result proves
that homocysteine levels are higher in the plasma areas than in the
cell areas.
[0041] Embodiments of the invention provide the ability to sample
specific components of whole blood in an efficient manner in a
single sampling. The present invention provides a time-saving and
space saving device and method to sample whole blood using minimal
amounts of sample (2-6 drops).
[0042] Although particular embodiments of the invention have been
described, other embodiments are within the scope of the following
claims. For example, the actions recited in the claims can be
performed in a different order and still achieve desirable
results.
* * * * *