CN102847477B - Magnetic stirring device and stirring method thereof - Google Patents

Abstract

A magnetic stirring device and a stirring method thereof, comprising two parts, a coil and a power supply, the coils are three pairs of orthogonal Helmholtz coils and a pair of Maxwell coils, and the axes of the three pairs of Helmholtz coils correspond to The X, Y, Z axes of the magnetic stirring device, the axis centers of the three pairs of Helmholtz coils intersect at the coordinate origin O, XOY is the horizontal plane, and the OZ axis is vertically upward. The axes of a pair of Maxwell coils coincide with the Z axis, and the centers of the axes coincide with the coordinate origin O. The currents in the four pairs of coils are controlled so that the four coils generate uniform magnetic fields and gradient magnetic fields with different time sequences to drive the movement of the nano magnetic particles, thereby realizing the mixing of the nano magnetic beads and the solvent.

Description

A kind of stirring method of magnetic stirring device

technical field

The invention relates to a magnetic stirring device and a stirring method thereof, in particular to a stirring and mixing device and a method of nano magnetic beads. the

Background technique

Since the birth of nano magnetic beads, it has attracted the attention of scientific researchers and has been successfully applied in the field of biochemical analysis. In recent years, nano-magnetic beads coated with specific antibodies, receptors, and single-stranded DNA have achieved great success in separating targets in complex samples. Compared with traditional separation methods, the use of nano-magnetic beads for the separation of biochemical samples with complex components can achieve separation and enrichment at the same time, greatly improving the separation speed and enrichment efficiency, and also greatly improving the sensitivity of analysis and detection. improve. At present, this magnetic microsphere has been widely used in many fields such as immunoassay, nucleic acid separation and extraction, cell sorting, and enzyme immobilization. the

An important step in the application of nanomagnetic field is to fully mix the nanomagnetic field with the reagent. In the existing technology, the test tubes containing the samples are generally mixed by mechanical vibration. Patent CN201249110Y puts the test tube containing nano-magnetic beads between two rotating magnets, and uses magnetic force to rotate the magnetic beads at the bottom of the test tube to achieve the purpose of mixing. But this patent has the motor of mechanical movement, and control mode is single, can't adjust mixing effect. the

Contents of the invention

The purpose of the present invention is to overcome the shortcoming of prior art, propose a kind of magnetic stirring device and nano-magnetic bead stirring method thereof. The invention adopts an automatic device without mechanical moving parts to fully mix the nano magnetic beads and reagents, which can improve the mixing efficiency and reduce the workload of experimenters, and can improve the reliability of the device and prolong the service life of the device. the

The present invention adopts the rotating magnetic field with variable frequency and amplitude to drive the magnetic field to mix, and the specific technical scheme is:

The magnetic field generating device of the present invention includes a coil and a power supply. the

The coils include three pairs of Helmholtz coils and one pair of Maxwell coils, a total of four pairs of coils. Three pairs of Helmholtz coils are installed orthogonally according to the size from small to large. The axes of the three pairs of Helmholtz coils correspond to the X, Y, and Z axes of the magnetic stirring device, and the three pairs of Helmholtz coils are called X. Axis, Y-axis, Z-axis Helmholtz coils. The axis centers of the three pairs of Helmholtz coils intersect at a point O, which is the origin of the Cartesian coordinate system OXYZ. XOY is a horizontal plane, and the OZ axis is vertically upward. The axis of a pair of Maxwell coils coincides with the Z axis, and the axis center of the Maxwell coil coincides with the coordinate origin O, which is called the Z-axis Maxwell coil. The power supply is a four-way current source with a CPU, and each of the X-axis, Y-axis, Z-axis Helmholtz coil and Z-axis Maxwell coil is connected to one current source. The magnetic field generated by the Z-axis Helmholtz coil is along the positive direction of the OZ axis, and the gradient of the magnetic field generated by the Z-axis Maxwell coil is along the positive direction of the OZ axis. the

The power supply is a four-way current source with a CPU, and the CPU can respectively control the direction and magnitude of the output current of the four-way current source. The four pairs of coils are respectively connected to one current source. the

In the present invention, the CPU controls four current sources to output currents of different sizes to four pairs of coils according to different time sequences, so as to realize the mixing of nano magnetic beads and reagents. Its principle and implementation method are as follows:

(1) Place the test tube containing the mixture of nano-magnetic beads and reagents vertically on the OZ axis;

(2) Passing a current into the Z-axis Helmholtz coil generates a magnetic field in the positive direction of OZ, and the field strength is greater than the saturation magnetization of the nano-magnetic beads, making the nano-magnetic beads magnetized;

(3) Feed current into the Z-axis Maxwell coil to generate a gradient magnetic field in the positive direction of OZ on the OZ axis, and the gradient magnetic field is sufficient to enable the magnetized nano-magnetic beads to overcome the resistance and move toward the positive direction of OZ;

(4) When most of the nano-magnetic beads move to the upper part of the mixture, stop the current to the Z-axis Helmholtz coil and the Z-axis Maxwell coil;

(5) A sinusoidal current with a phase difference of 90 degrees is passed into the X-axis Helmholtz coil and the Y-axis Helmholtz coil to generate a rotating magnetic field in the XOY plane, and the field strength of the rotating magnetic field is greater than that of nano-magnetic beads The saturation magnetization makes the nano-magnetic beads magnetized; then a current is passed through the Z-axis Maxwell coil to generate a gradient magnetic field, and the gradient magnetic field is sufficient to enable the magnetized nano-magnetic beads to overcome resistance and generate motion;

(6) Stop the current to each coil, and repeat (2)-(5) until the nano-magnetic beads and the reagent are evenly mixed. the

The effect and benefit of the present invention are: by adding different magnetic fields around the test tube to realize the full mixing of nano magnetic beads and reagents, the whole device realizes mixing by changing the current in the coil, the method is simple, and the amplitude of the current in the coil can be controlled and frequency to achieve different mixing effects. the

Description of drawings

Fig. 1 is a schematic diagram of a magnetic stirring device of the present invention;

Fig. 2 is a schematic diagram of the connection of the magnetic stirring device of the present invention. the

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. the

The magnetic field generating device of the present invention includes a coil 2 and a power source 1 . the

As shown in FIG. 1 , the coils 2 are three pairs of orthogonal Helmholtz coils and a pair of Maxwell coils. Three pairs of orthogonal Helmholtz coils are installed in orthogonal nesting from small to large sizes, and the axes of the three pairs of Helmholtz coils correspond to the X, Y, and Z axes of the magnetic stirring device. The axis centers of the three pairs of Helmholtz coils intersect at point O, which is the origin of the Cartesian coordinate system OXYZ. XOY is a horizontal plane, and the OZ axis is vertically upward. The axes of the pair of Maxwell coils coincide with the Z axis, and the axis centers of the Maxwell coils coincide with the coordinate origin O. Three pairs of orthogonal Helmholtz coils and a pair of Maxwell coils are respectively connected to four current sources, and the CPU controls the magnetic fields generated in three axes by controlling the output current of the four current sources. The Helmholtz coil in the X-axis is coil X, the Helmholtz coil in the Y-axis is coil Y, the Helmholtz coil in the Z-axis is coil Z, and the Maxwell coil in the Z-axis is coil MZ. the

The power supply 1 is a four-channel current source with a CPU, and the CPU can directly control the output current of each current source. the

Figure 2 is a schematic diagram of the overall connection of the magnetic stirring device of the present invention. The current sources 1 to 4 are sequentially connected to the Helmholtz coil X of the X axis, the Helmholtz coil Y of the Y axis, the Helmholtz coil Z of the Z axis, and the Maxwell coil MZ of the Z axis. the

The method of magnetic stirring of the present invention is as follows:

(1) Place the test tube containing the mixture of nano-magnetic beads and reagents vertically on the OZ axis;

(2) Passing a current into the coil Z generates a magnetic field in the positive direction of OZ, and the field strength is greater than the saturation magnetization of the nano-magnetic beads, so that the nano-magnetic beads are magnetized;

(3) Passing current into the coil MZ generates a gradient magnetic field along the positive direction of OZ on the OZ axis, and the gradient magnetic field is sufficient to enable the magnetized nano-magnetic beads to overcome the resistance and move toward the positive direction of OZ;

(4) When most of the nano-magnetic beads move to the upper part of the mixture, stop the current to the coil Z and the coil MZ;

(5) A sinusoidal current with a phase difference of 90 degrees is passed into the coil X and coil Y to generate a rotating magnetic field in the XOY plane, and the field strength amplitude of the rotating magnetic field is greater than the saturation magnetization of the nano-magnetic beads, so that the nano-magnetic beads are magnetized; then A current is passed through the Z-axis Maxwell coil to generate a gradient magnetic field, and the gradient magnetic field is sufficient to enable the magnetized nano-magnetic beads to overcome resistance and generate motion;

(6) Stop the current in each coil, and repeat steps (2) to (5) until the nano-magnetic beads and the reagent are evenly mixed. Changing the magnitude of the magnetic field generated in each coil in the above step and the frequency of the rotating magnetic field in step (5) can change the mixing effect of the solution. the

Claims (1)

1. a magnetic agitation method, the magnetic stirring apparatus that the method uses comprises coil and power supply; Described coil is three to orthogonal Helmholtz coil and a pair Maxwell's coil totally four pairs of coils, the X, Y, Z axis of the corresponding magnetic stirring apparatus of axis difference of three pairs of described Helmholtz coils, the axle center of three pairs of Helmholtz coils meets at the initial point O of rectangular coordinate system OXYZ, XOY is horizontal plane, and OZ axle straight up; The axis of a pair described Maxwell's coil overlaps with Z axis, and the axle center of a pair described Maxwell's coil overlaps with origin of coordinates O; Described power supply is the four road current sources of band CPU, and four connect a road current source respectively to described coil,

It is characterized in that described stirring means is:

(1) test tube that the mixed liquor of nanometer magnetic bead and reagent is housed vertically is placed on OZ axis;

(2) in Z axis Helmholtz coil, pass into electric current produce towards the magnetic field of OZ positive direction, the amplitude of field strength in this magnetic field is greater than the saturation magnetization of nanometer magnetic bead, and nanometer magnetic bead is magnetized;

(3) in Z axis Maxwell's coil, pass into the gradient magnetic that electric current produces OZ positive direction on OZ axis, described gradient magnetic is enough to make magnetized nanometer magnetic bead can overcome resistance towards OZ positive movement;

(4) when most of nanometer magnetic bead moves to mixed liquor top, the electric current led in Z axis Helmholtz coil and Z axis Maxwell's coil is stopped;

(5) in X-axis Helmholtz coil and Y-axis Helmholtz coil, pass into phase difference is the rotating excitation field that the sinusoidal current of 90 degree produces in XOY plane, the amplitude of field strength of described rotating excitation field is greater than the saturation magnetization of nanometer magnetic bead, and nanometer magnetic bead is magnetized; Then in Z axis Maxwell's coil, pass into electric current produce gradient magnetic, described gradient magnetic is enough to make magnetized nanometer magnetic bead can overcome resistance and produces motion;

(6) stop the electric current in each coil, repeat step (2) ~ step (5) until nanometer magnetic bead mixes with reagent.