TECHNICAL FIELD
[0001] The present invention relates to the field of chemical analysis, and in particular,
to a centrifuge filtration tube.
BACKGROUND OF THE INVENTION
[0002] For the purpose of various research, it is often necessary to liquefy samples such
as soil, meat, water, flora, and fauna, etc., and to separate and remove small solid
particles from the treatment liquids before they can be used for testing in large-scale
high-precision instruments (such as flow analysis injectors, liquid chromatography
mass spectrometry, etc.). Otherwise, these particles will block or wear off the instruments'
sample input channels, which can cause instrument failures and shorten their life
expectancy. Conventionally, solutions for this problem are filtering or pressurized
filtering. But for high volume samples, these methods are inefficient, time-consuming,
and laborious.
[0003] Patent application
CN202290316U has described a double-layer pipe in which an inner tube is provided with a plurality
of openings for blocking polymeric pellets which only allows liquid to flow out under
gravity (at rest). The function of the disclosed device is equivalent to a screen,
which can only conduct simple solid-liquid separation treatment. The disclosed device
can neither produce controlled liquid flow, nor achieve separation of hydrophilic
and hydrophobic liquids.
SUMMARY OF THE INVENTION
[0004] The main object of the present invention is to provide a centrifuge filtration tube
which makes it more efficient, quick, and convenient for analyses of certain biological
or chemical samples.
[0005] The present invention includes the following technical features:
[0006] A centrifuge filtration tube includes a second centrifuge tube (2) and a first centrifuge
tube (1) housed in the centrifuge tube (2). The first centrifuge tube (1) includes
one or more constant-volume vents (7) and multiple pores (4) on a side wall of the
first centrifuge tube (1). The one or more constant-volume vents (7) are located above
the pores (4). A filtering membrane (3) covers the pores (4).
[0007] Further, the one or more constant-volume vents (7) can be located in an upper portion
of the side wall of the centrifuge tube (1). The pores (4) can be located in a middle
portion of the side wall of the centrifuge tube (1).
[0008] Further, the one or more constant-volume vents (7) can be located in a top cover
of the centrifuge tube (1). The pores (4) can be located in a middle portion of the
side wall of the centrifuge tube (1).
[0009] Further, the filtering membrane can be positioned on an inner wall of the centrifuge
tube (2) and covers the pores (4) in the side wall of the first centrifuge tube (1).
[0010] Further, the filtering membrane can be a microporous membrane.
[0011] Further, the filtering membrane can be a polypropylene microporous membrane.
[0012] Further, the filtering membrane can be a polytetrafluoroethylene air filtration membrane.
[0013] Further, the filtering membrane can be a hydrophobic filter.
[0014] The centrifuge filtration tube of the present invention includes a microporous membrane
coated on the inner tube having pores. Since the microporous membrane has a large
surface tension, a liquid inside the microporous membrane does not flow out when only
gravity is present (still state); this state is equivalent to a closed valve. When
the centrifuge filtration tube is put to high-speed rotation in a centrifuge, the
centrifugal force overcomes the liquid surface tension, which allows the liquid to
flow out of the microporous membrane; this state is equivalent to an open valve. The
pores in the membrane function as a valve under the control of centrifuge forces,
which can be closed or opened by centrifugal rotations; its role is completely different
from the screen using in conventional technologies. In practice, the present invention
only requires for a low-speed centrifugal rotation (2000-4000 rpm) for a short period
(3-5 min), which is particularly suitable for scientific research workers handling
a large number of samples, and can save a lot of manpower and time.
[0015] The present invention can be implemented by the following technologies: a plastic
centrifuge filtration tube comprising a centrifuge tube 1 having one or a plurality
of pores in the middle of its side wall. The pores in the side wall are sealed with
a layer of membrane. The side wall of the centrifuge filtration tube 1 includes a
constant-volume vent 7 for balancing the internal and external air pressures during
centrifugation. The centrifuge tube 1 is placed in another 50 mL commercial centrifuge
tube 2. When the test is started, a sample liquid suspension is placed in the centrifuge
tube 2, and the centrifuge tube 1 with filtration pores on its side wall is placed
in the centrifuge tube 2. The centrifuge is started. At this time, the portion of
the liquid having the liquid level higher than the pores is moved into the centrifuge
tube 1 by centrifuge forces, to achieve the goal of rapid clearing of the sample suspension.
[0016] Compared with conventional technologies, the present invention includes the following
advantageous effects: it only requires for a low-speed centrifugal rotation (2000
- 4000 rpm) for a short period (3-5 min), which is particularly suitable for scientific
research workers handling a large number of samples, and can save a lot of manpower
and time.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017]
Figure 1 is a schematic diagram of the disclosed centrifuge filtration tube;
Figure 2 is a partial cross-sectional view of the centrifuge filtration tube;
wherein 1 - small centrifuge tube, 2 - large centrifuge tube, 3 - filtering membrane;
4 - pore, 5 - a top cover of the small centrifuge tube 1,6 - a top cover of the large
centrifuge tube, 7 - constant-volume vent, 11 - a side wall of the small centrifuge
tube, 21 - a side wall of the large centrifuge tube, and 31 - a cross section of the
filtering membrane.
DETAILED DESCRIPTION OF IMPLEMENTIONS
[0018] The present invention is now described in further detail with reference to the accompanying
drawings,
[0019] Figure 1 is a schematic diagram for a centrifuge filtration tube, including: a small
centrifuge tube 1; a large centrifuge tube 2, a filtering membrane 3 attached to the
side wall of the small centrifuge tube 1; one or more pores 4 on the small centrifuge
tube 1, a top cover 5 of the small centrifuge tube 1, a top cover 6 of the large centrifuge
tube 2, and a constant-volume vent 7 on the upper portion of the small centrifuge
tube 1 (the constant-volume vent 7 may be provided on the top cover 5 of the small
centrifuge tube 1). A large hole is opened in the top of the large centrifuge tube
2 through which the small centrifuge tube 1 is placed into the large centrifuge tube
2. The constant-volume vent 7 is opened in the upper portion of the small centrifuge
tube 1 for exhausting air and maintaining constant volume.
[0020] Figure 2 is a cross-sectional view of the centrifuge filtration tube. The small centrifuge
tube 1 includes a side wall 11. The large centrifuge tube 2 includes a side wall 21.
The filtering membrane 3 has a cross section 31.
[0021] Example 1: place the liquid to be cleared in a commercially available centrifuge
tube 2, place the centrifuge tube 1 therein, and start the centrifuge. Wait until
the liquid flows into the centrifuge tube 1 through the pores in the side wall of
the centrifuge tube 1. Depending on different pore sizes of the pores, the filtering
membrane can block macromolecules or large particles away outside of the centrifuge
tube 1. A relatively pure solution can thus be obtained in the centrifuge tube 1.
[0022] Example 2: The filtering members affixed to the sidewall of the centrifuge tube 1
can be formed by different types of films such as polypropylene microporous membrane,
a polytetrafluoroethylene air filtration membrane, or a hydrophobic membrane, etc.
1. A centrifuge filtration tube (1), comprising:
a first centrifuge tube (1) comprising a side wall that includes one or more constant-volume
vents (7) and multiple pores (4), wherein the constant-volume vents (7) are located
above the pores (4);
a filtering membrane (3) that covers the pores (4); and
a second centrifuge tube (2) in which the first centrifuge tube (1) is housed.
2. The centrifuge filtration tube of claim 1, wherein the one or more constant-volume
vents (7) are located in an upper portion of the side wall of the centrifuge tube
(1), wherein the pores (4) are located in a middle portion of the side wall of the
centrifuge tube (1).
3. The centrifuge filtration tube of claim 1, wherein the centrifuge tube (1) include
a top cover, wherein the one or more constant-volume vents (7) are located in the
top cover of the centrifuge tube (1), wherein the pores (4) are located in a middle
portion of the side wall of the centrifuge tube (1).
4. The centrifuge filtration tube of claim 1, wherein the filtering membrane is positioned
on an inner wall of the centrifuge tube (2) and covers the pores (4) in the side wall
of the first centrifuge tube (1).
5. The centrifuge filtration tube of claim 1, wherein the filtering membrane is a microporous
membrane.
6. The centrifuge filtration tube of claim 5, wherein the filtering membrane is a polypropylene
microporous membrane.
7. The centrifuge filtration tube of claim 5, wherein the filtering membrane is a polytetrafluoroethylene
air filtration membrane.
8. The centrifuge filtration tube of claim 5, wherein the filtering membrane is a hydrophobic
filter.