RU2697275C1 - Magnetic support for test tubes for extraction and purification of nucleic acids and/or macromolecules from biological sample - Google Patents

Abstract

FIELD: biotechnology.SUBSTANCE: invention relates to molecular biotechnology and biochemistry and can be used for manual extraction and purification of macromolecules from biological samples. Magnetic tripod for extraction and purification of nucleic acids from liquid samples contains upper plate with holes for installation of test tubes with macromolecules and magnetic particles, lower plate with magnets and walls. Magnetic support has a holder of test tubes with carrying handles, an axis with a handle and one or several cams arranged on the axis. Each of cams has two or more sites to ensure continuous movement of lower plate with magnets in vertical plane and their fixation in positions in accordance with number of sites. Each magnet has a ring shape and is equipped with a shell from corrosion-resistant material. Each test tube is placed inside the ring of the corresponding magnet. Holder of test tubes with carrying handles is located on upper plate. Upper plate and holder of test tubes with handles are made from transparent material. Holes in upper plate are provided with optical windows. Holder of the tubes also has holes and optical windows. Upper plate comprises additional holes in zone of absence of magnetic field.EFFECT: invention ensures achievement of technical result consisting in improvement of quality and convenience of extraction and purification of nucleic acids and other macromolecules from biological samples at simultaneous provision of protection of magnets against corrosion during disinfection.1 cl, 2 dwg

Description

The invention relates to the field of molecular biotechnology and biochemistry.

The magnetic tripod is designed for manual isolation and purification of nucleic acids and other macromolecules from biological samples (in particular, from the blood and tissue of patients).

The magnetic tripod is mainly used in conjunction with nucleic acid analyzers based on the real-time polymerase chain reaction (PCR) method to meet the needs of medicine and scientific research.

After lysis (destruction of cells), the macromolecules are in test tubes in the form of a solution along with impurities. Before installation in a magnetic rack, magnetic particles coated with glass are added to test tubes with macromolecules. Macromolecules bind to magnetic particles. After installing the tubes in a magnetic rack, magnetic particles with macromolecules are concentrated by magnets on the walls of the tubes, then solutions with impurities are removed from the tubes using a pipette with interchangeable tips. After this, the tubes are filled with new washing liquid, the washing process is repeated several times. After a series of washes, tubes with magnetic particles without liquid are transferred to an area where there is no magnetic field. An eluting liquid is added to the tubes, into which the macromolecules pass from the surface of the magnetic particles. The eluting fluid with macromolecules is separated from the magnetic particles and used for analysis.

Known patent "Magnetic separation device" (magnetic separation device, US patent No. 7829026 B2, CL B01L 1/00, 07/26/2007). The device comprises a housing with holes for test tubes and a housing with magnets connected in such a way that the first housing can move away from the second by such a distance that there is no magnetic field effect of the magnets on the tubes. The device can be performed with two cases with test tubes and two cases with magnets. The disadvantage of this device is the presence of moving parts, which affects the complexity and reliability of the device. At the same time, the device has impressive dimensions.

Known patent "Magnetic tube nuts" (Magnetic tube rack, US patent No. 9358542 B2, CL B01L 9/06, B66F 11/00, 05/21/2014). The tripod has a stand containing the upper and lower plates located at some distance from each other, and the magnet holder in the form of a plate with holes in which the permanent magnets are inserted. The top plate has 2 rows of test tube holes. The rack allows the magnet holder to slide between 2 rows of tubes. The disadvantage is that the tripod is limited to 2 rows of tubes.

Known patent "Magnetic tube rack for diagnostic assays" (Magnetic tube rack, US patent No. 4895650, CL B03C 1/02, 02/25/1988).

The tripod consists of a housing with holes for test tubes and a housing with magnets. The magnets are fixed to the bottom of the case so that each magnet is located between 2 rows of tubes. The disadvantage is the inconvenience of removing the tubes from the openings.

Known patent "Magnetic particle separating device, and method of separating and purifying nucleic acid or protein using the same" (Magnetic particle separation device, US patent No. 20160368001 A1, CL B03C 1/288, 09/09/2013). The device consists of a base with magnets made in the form of rods, and a plate with holes for tubes. The device is designed so that the magnets are located between the tubes.

The disadvantage is the design complexity: to remove the tubes from the magnets, it is necessary to separate the plate with the tubes and the base with magnets.

The closest known by technical nature and purpose is the patent “Magnetic nuts” (Magnetic tripod, US patent No. 20170080430, CL B01L 9/06, B03C 1/02, B03C 1/03, B01L 9/00, 09/17/2015).

The well-known magnetic tripod solves the problem of reducing the number of components, as well as fixing the tubes in the wells due to the friction forces arising between the tubes and magnets.

This magnetic tripod contains a top plate with holes, a bottom plate, walls, tubes and magnets. In each hole of the upper plate there are tubes with a suspension of macromolecules adsorbed on magnetic particles, while the upper and lower plates are connected by walls. The magnets have a cylindrical appearance and are located on the bottom plate in such a way that each magnet occupies part of the space of the holes with the tubes to create friction forces and fix the tubes. The disadvantages of the known magnetic tripod can be recognized as the absence of a zone with holes without magnets, as well as visual contact with test tubes.

A common drawback of all known analogues is the lack of protection of the magnets against corrosion during external disinfection of the tripod. Another drawback is the lack of technical solutions aimed at the distribution of the magnetic field acting on the magnetic particles in the test tube: magnetic particles with macromolecules form dense magnetic lumps on the side wall of the test tube that hold impurities. Such impurities cannot be removed from the lumps during a single wash, which reduces the effectiveness of genetic tests.

The aim of the invention is to reduce the amount of impurities in the sample, providing visual control of the process of concentration of magnetic particles, ensuring the separation of macromolecules from magnetic particles, as well as protecting magnets from corrosion during disinfection.

This goal is achieved due to the fact that the known magnetic tripod containing a top plate with holes for installing tubes with macromolecules and magnetic particles, a bottom plate with magnets and walls, is equipped with a tube holder with carrying handles, each magnet having the shape of a ring and equipped with a sheath made of corrosion-resistant material, each tube is located inside the ring of the corresponding magnet, the tube holder with carrying handles is located on the top plate, the top plate and holder s tubes with handles made of transparent material in the top plate are provided with optical windows openings, tubes holder also has holes for the tubes and the optical window, the top plate further comprises a hole in the non-magnetic field zone.

A magnetic tripod can be equipped with one or several cams with two or more platforms along the perimeter, a handle and an axis, providing continuous movement of the bottom plate with magnets in the vertical direction and fixing them in positions in accordance with the number of platforms.

The present invention is illustrated by drawings, on which:

in FIG. 1 is a drawing of a magnetic tripod, top view;

in FIG. 2 - two cuts of a magnetic tripod.

The magnetic tripod contains an upper plate 1 with holes 2 for installing tubes 3 with macromolecules and magnetic particles, a lower plate 4 with magnets 5 and walls 6. On the upper plate 1 is a tube holder 7 with handles 8 for carrying. Each magnet 5 has the shape of a ring and is provided with a shell of corrosion-resistant material, with each tube 3 located inside the ring of the corresponding magnet 5. As an example, one tube 3 is installed in the drawings. The upper plate 1 is made of transparent material, the holes 2 in the upper plate are equipped with optical windows 9. The tube holder 7 also has holes 2 for installing the tubes 3 and optical windows 9. The upper plate contains additional holes 10 in the absence of a magnetic field.

In a magnetic tripod with the help of one or more cams 11, the lower plate 4 with the magnets 5 is continuously moved in the vertical direction and locked in two or more positions. To do this, on the working surface of the cams 11 there are several platforms 12. The rotation of the cams 11 is carried out using the handle 13. The force during the rotation of the cams 11 is transmitted from the handle 13 through the axis 14. The axis 14 is based on bearings that are mounted in the walls 6.

The magnetic tripod works as follows.

The operator installs tubes 3 containing a suspension of magnetic particles with adsorbed macromolecules in the holes 2. Each magnet 5 has a ring shape, so the magnetic particles on the wall of each tube 3 are also in the form of a flat ring. In this case, the washing conditions are improved to remove unwanted impurities, and an increase in the purity of macromolecules is achieved, since the magnetic particles do not form a dense lump.

External lighting penetrates through the transparent upper plate 1 and the tube holder 7, while the operator has the opportunity to observe the process of concentration of magnetic particles through optical windows 9.

To implement the process of separating macromolecules from magnetic particles after completion of the concentration of macromolecules and a series of washes, the tubes 3 are transferred using the tube holder 7 to additional holes 10 located at such a distance from the magnets that there is no magnetic field on the tubes. Test tubes 3 are filled with a solution into which macromolecules pass from the surface of magnetic particles.

After each cycle of macromolecule isolation, there is the possibility of complete disinfection. The corrosion protection of magnets 5 during disinfection is provided by a shell made of a corrosion-resistant material.

Using the handle 13, the lower plate 4 with magnets 5 provides the possibility of continuous movement and fixing in one of the possible positions when the lower plate 4 is supported on the corresponding platform 12 of the rotary cams 11.

In the first position of the lower plate 4 with magnets 5 on the wall of each tube 3, the magnetic particles together with the macromolecules are arranged in the form of a flat ring at the level of the magnets 5. After continuous movement and stopping of the lower plate 4 with magnets 5 in the second position, the magnetic particles together with the macromolecules move to a new level of magnets 5. When moving magnetic particles, the remaining impurities pass into the solution. By moving the magnets 5, it is possible to repeatedly wash and use tubes 3 of greater height and greater volume, for example 2 ml or more.

In the lower position, the magnets 5 are at a distance at which there is no magnetic field on the tubes 3, while the tubes 3 are filled with an eluting liquid, into which the macromolecules pass from the surface of the magnetic particles.

The proposed technical solutions of a magnetic tripod can reduce the amount of impurities in the sample, provide visual control of the concentration of magnetic particles, ensure the separation of macromolecules from magnetic particles, and protect the magnets from corrosion during disinfection.

Claims (1)

A magnetic stand for the isolation and purification of nucleic acids from liquid samples, containing a top plate with holes for installing tubes with macromolecules and magnetic particles, a bottom plate with magnets and walls, characterized in that it is equipped with a tube holder with carrying handles, an axis with a handle and placed on the axis of one or more cams, each of which has two or more platforms, to ensure continuous movement of the lower plate with magnets in the vertical plane and their fixation in positions in according to the number of pads, each magnet has a ring shape and is provided with a shell of corrosion-resistant material, each tube is located inside the ring of the corresponding magnet, the tube holder with carrying handles is located on the upper plate, the upper plate and the tube holder with handles are made of transparent material, the holes in the upper plate are provided with optical windows, the tube holder also has holes and optical windows, the upper plate contains additional holes in the zones absence of a magnetic field.

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