SU1712855A1 - Method for concentrating biological objects in suspensions - Google Patents

Abstract

The invention relates to methods for concentrating bioobjects in suspension and can be used in microbiology, medicine, and scientific research. The object of the invention is to ensure the selective concentration of bioobjects according to their dipole moment and polarizability in a cyclic mode of operation. The method includes filling the chamber with a suspension of bioobjects with successively installed electrodes and applying an alternating electrical current to the electrodes to create a non-uniform electrical field in the intervals between the electrodes 14 in the form of a traveling electric wave with variable phase velocity and a surge gradient in each cycle of the concentration of bioobjects. The camera in the device is in the form of a channel, and the electrodes are in the form of rings connected to a source of alternating voltage through a switch and resistors. 2 ill. ^^

Description

The invention relates to means and methods for concentrating bioobjects in suspension and can be used in microbiology, medicine, and scientific research.

It is known that the magnitude of the dipole moment and the polarizability of biological objects correlate with their immunogenicity. The magnitude of the dipole moment of a bio-object can be used to evaluate its immunogenicity: the greater the dipole moment of a biological object, the greater its immunogenicity. In connection with this, there is a problem associated with the separation and concentration of objects of one subpopulation with the same dipole moments and polarizability from the suspension; si containing a mixture of objects with different dipole moments and polarizability; for further study of the concentrate.

There are known methods and means of concentrating bioobjects according to various parameters; by weight, density, size, interaction with chemicals, etc. The closest technical solutions are methods and devices for concentrating bioobjects by the magnitude of electrical charge.

There is a known method for separating and concentrating animal cells, including introducing into the separator a cell culture of animal cells and media for suspending these cells. The medium is an aqueous polymer system, one of the phases of which has electrophoretic mobility in an electrostatic field. An electrostatic field is formed in the chamber between the electrodes and the cell concentrate is removed from one of the electrodes.

The disadvantage of this method is the impossibility of selectively concentrating cells and other bioobjects according to their dipole moment and polarizability.

Closest to the proposed method is the fusion of living cells. The method involves filling the working cell with a successively placed electrode with a suspension of cells and applying alternating current to the electrodes to create a non-uniform electric field between the electrodes and removing the cells in the area of their concentration.

The disadvantage of the prototype method is the impossibility of selectively converting bioobjects according to their dipole moment and polarizability.

The purpose of the invention is to provide selective concentration of bioobjects according to their dipole moment and polarizability in a cyclic mode to obtain small amounts of concentrate.

The goal is achieved by the fact that the working volume of the chamber with successively installed electrodes in it is filled with a suspension of biological objects, for example, microorganisms, viruses, or culture cells. An alternating electric current is applied to the suspension. Bio-objects are removed at the site of their concentration. An inhomogeneous electric field is formed cyclically in the form of a traveling wave with variable phase velocity and intensity gradient in each cycle of concentration of objects, with the magnitude of the electric field intensity gradient and the phase velocity of wave propagation chosen from the ratio

PgracSE 6 (p,

where P is the dipole moment of the bio-object;

grad E is the gradient of electric field intensity;

J / is the viscosity of the slurry;

g is the radius of the bioobject;

Vy is the phase velocity of propagation of an electric wave relative to the suspension of a bioobject.

FIG. 1 shows a diagram of an apparatus for implementing a method for concentrating bioobjects in a suspension; in fig. 2 is the distribution of the gradient E of the electric field along the length of the channel 6, different instants of time ti, t2tn.

A device for implementing a method for concentrating bioobjects in a suspension consists of a chamber made in the form

channel 1 having a supply funnel 2 on one side, a bioobject suspension, and the other has a tank 3 for receiving a bioobject concentrate with a valve 4 and a branch pipe with

crane 5 dl, drain this concentrate. The length of the channel 1 is installed in series electrodes 6, made in the form of rings. In addition, the device is equipped with a switch 7 with movable 8 and fixed

contacts 9. The movable contacts 8 are mounted on a rotational drive 10. Electrodes 6 are connected via pins 8 and 9 of switch 7 and resistors 11c with a source of alternating voltage and

are electrical circuits 12-29 with different resistances (fig. 1) for forming along the channel 1 traveling wave a gradient of intensity of an electric field with a constant amplitude (fig. 2).

The method of concentrating bioobjects in suspension is carried out using the device as follows.

Suspension of biological objects (macromolecules, viruses, bacteria, cells) from the original

the concentration is fed through the funnel 2 to the channel 1 with the valve 4 open and the valve 5 closed. The device is supplied with alternating voltage and the rotational drive of the disk 10 of the switch 7c with a frequency of 0.01-0.001 Hz is turned on. The switch 7 sequentially switches the moving contacts 8 relative to the fixed contacts 9, as a result of which the resistance in the circuits 12-29 and, consequently, the voltage Uo on the electrodes 6 in these electrical circuits changes periodically. The sequence of voltage variation on the electrodes 6 is visible from fig. 1. Between the electrodes 6, a gradient-intensity of the electric field with three antinodes and knot-; M, which are displaced along the channel length at the instants of time ti, t2, ..., tn, i.e., a traveling electric wave arises with variable phase velocity and electric field gradient (gradient E). The switching time of the contacts of the switch 7 determines the speed of the traveling wave, and the amplitude of the alternating voltage determines the gradient of the electric field intensity. These parameters are chosen based on the equality

Pgrad E 6 vyi.

Moreover, the traveling wave propagation speed v determines the switching time t of the switch 7 .L, where L is the distance between adjacent electrodes 6.

A running electric wave acts on living bioobjects (viruses, cells) with a certain dipole moment, for which the condition of equality of the force acting from the electric field and the force of viscous friction from the liquid (suspension) when the biological object moves at a speed of grad E 6; G) / g v, and enthralls these bioobjects in the direction of the tank 3. After the process of selective concentration of bioobjects with a certain dipole moment and polarizability is finished, channel 1 is blocked by valve 4 and the bioobial concentrate The cells are drained after opening the crane 5. Next, from channel 1, the rest of the suspension is removed, a new portion of the suspension is fed and the cycle is repeated. If it is necessary to isolate bioobjects with other dipole moments from the rest of the suspension, the following parameters are changed; the voltage Uo or the phase velocity vf of the propagation of an electric wave relative to the suspension of biological objects by changing the speed of rotation of the disk 10 of the switch 7.

The feasibility of the method is verified by isolating and concentrating the Vero cells from the suspension. The suspension includes a mixture of the following components: Vero cells, serum proteins, amino acids, glucose and vitamins, as well as other components with different dipole moments. For example, it is known that the dipole moments of macromolecules have a size of 10 Debye, bacteria are 10 –10 Debye, and according to experimental data, Vero cells have a dipole moment of Debye. In the experimental model, the gradient of the electric field strength between the electrodes is 10® V / m. The velocity v of movement of individual Vero cells at a concentration of 1-5 µm / s. During the experiments, it was possible to concentrate and isolate Vero cells.

with the dipole moments of an individual cell on the order of 0; 410 Debye ± 50% and polarizability 0, m from a suspension having biological objects with different dipole 5 moments and polarizability.

The technical effect of using the proposed method is to provide selective concentration of bioobjects of one subpopulation according to their distant moment and polarizability in a cyclic mode, which allows isolating bioobjects (viruses, bacteria, cells) with a suspension with a certain immunogenicity to obtain, for example, drugs

5 with all biological activity. The cyclic concentration mode of bioobjects allows working with a small amount of expensive bioobjects suspension.

Claims (1)

The invention of the method for concentrating bioobjects in a suspension, comprising applying an alternating electric field to the suspension, 5 characterized in that, in order to ensure the selective concentration of bioobjects according to their dipole moment and polarizability, a non-uniform electric field is cyclically formed as 0 traveling wave with variable phage speed and gradient of intensity in each cycle of concentration of objects, and the magnitude of gradient of intensity grad E and phase velocity vy of propagation of the wave are taken out of Pgrad E 6lg; guu. where P is the dipole moment of the bio-object; 0 grad E-gradient of electric field intensity; D) - viscosity of the suspension; g is the radius of the bioobject; Vy is the phase velocity of propagation of 5 electric waves relative to the suspension of a bioobject. fig i / fЯ gfradB fig 2 2