Method and instrument for measuring cell collapse degree

Abstract

The invention discloses a method and an instrument for measuring the cell disintegration degree, and relates to the technical field of cell disintegration measurement, the method is based on the electrical impedance characteristic of a living body, and the electrical impedance of the living body refers to the resistance characteristic and the capacitive reactance characteristic encountered when current flows through living body tissue, and the current flowing resistance capacity. Before and after the organism is treated by the high-voltage pulse electric field, the impedance value or conductivity value of the organism is respectively measured at low frequency and high frequency by using a measuring instrument. And then the cell collapse index is calculated through a calculation formula, and a quantifiable measurement standard is provided for whether the high-voltage pulse electric field treatment is successful or not and for optimizing the optimal application parameters of the high-voltage pulse electric field.

Description

Technical Field

[0001] The present invention relates to the technical field of cell collapse measurement, and in particular to a method and instrument for measuring the degree of cell collapse. Background Art

[0002] High-voltage pulse electric field pretreatment of raw materials, softening potatoes, sweet potatoes, and cassava has become a standard process in the potato processing industry. At the same time, high-voltage pulse electric field pretreatment also has a positive effect on agricultural product osmotic dehydration and hot air drying. In order to provide a quantifiable measure of whether the high-voltage pulse electric field treatment is successful, and to optimize the optimal application parameters of the high-voltage pulse electric field, the present invention proposes a method and instrument for measuring the degree of cell collapse. Summary of the invention

[0003] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0004] To solve the above technical problems, the present invention provides the following technical solutions: a method for measuring the degree of cell collapse, which is based on the electrical impedance characteristics of a living body. The electrical impedance of a living body refers to the resistance and capacitance characteristics encountered when current flows through the tissue of a living body, which are the ability to resist the flow of current.

[0005] People have observed the electrical resistance characteristics of organisms very early and have also given the reason why organisms produce resistance: when electrolyte ions in extracellular fluid and intracellular fluid move in an electric field, the viscous medium and narrow channels hinder the movement of ions.

[0006] Biological cell membranes have both capacitance and resistance properties. The electrical model of the cell membrane is a leaky capacitor. The lipid bilayer is equivalent to a capacitor, and the protein ion channel is equivalent to a resistor.

[0007] The cell membrane is composed of a lipid bilayer. The inside of the lipid bilayer is filled with dielectrics. The outside and inside of the membrane are filled with extracellular fluid and intracellular fluid, respectively. We regard them as conductive solutions. Therefore, the cell membrane composed of a lipid bilayer is equivalent to a capacitor in terms of electrical properties. The lipid bilayer is the two plates of the capacitor, which are connected to the conductive extracellular fluid and intracellular fluid, respectively, and the middle of the two plates is filled with dielectrics. However, the structure of the cell membrane is not only composed of lipid bilayers, but also of proteins embedded in it. Some of these proteins are so-called "ion channels". Their existence allows ions to be transported across the membrane. In physics terms, the cell membrane capacitor is a "leaky capacitor". Current can pass through the dielectric between the two plates. The leaky capacitor can be represented by an ideal capacitor and a resistor in parallel. The leakage current passes through the capacitor through the resistor.

[0008] An organism is composed of a large number of cells and can be regarded as a collection of many cells. The cell fluid resistance and cell membrane capacitance of the entire cell collection, after very complex series and parallel connections, obtain the equivalent resistance R and equivalent capacitance C representing the entire organism.

[0009] When low-frequency current flows through an organism that has not been treated with a high-voltage pulse electric field, the impedance is relatively large. This is because the untreated organism exhibits resistance and capacitive reactance characteristics to low-frequency current. The smaller the frequency, the greater the capacitive reactance.

[0010] For organisms that have not been treated with high-voltage pulse electric fields, the impedance decreases when high-frequency current flows through the organisms. This is because the untreated organisms mainly show resistance characteristics to high-frequency currents, and the higher the frequency, the smaller the capacitive reactance.

[0011] When a biological body is treated with a high-voltage pulse electric field, the impedance is small when a low-frequency current or a high-frequency current flows through the biological body. This is because the high-voltage pulse electric field causes electroporation of the cell membrane - the lipid bilayer is destroyed. At this time, the biological body is equivalent to the equivalent capacitor C being broken down, thereby partially or completely losing the capacitance characteristics. Because of the electroporation of the cell membrane - the formation of many ion channels, the equivalent resistance value R of the biological body is sharply reduced.

[0012] In summary, by using measuring instruments to measure the impedance of the organism at low and high frequencies before and after it is treated with a high-voltage pulse electric field, we can calculate the collapse index of the organism's cells.

[0013] Since conductivity is defined as the inverse of impedance, the biological cell collapse index Z is calculated by the following formula;

[0014]

[0015] Where z is the cell collapse index, 0≤z≤1, and the z value varies between 0 for intact cells and 1 for complete collapse; σ' is the conductivity of the sample treated with a pulsed electric field at a low frequency, mS cm -1 ;σ——Conductivity of untreated sample measured at low frequency, mS·cm -1 ; σ h ——Measurement of conductivity of untreated samples at high frequency, mS·cm -1 ;σ′ h ——Measure the conductivity of samples treated with pulsed electric fields at high frequencies, mS·cm -1 .

[0016] As a preferred embodiment of the method for measuring the degree of cell damage described in the present invention, in this method, the low frequency range is 1-10 kHz, and the high frequency range is greater than 50 MHz.

[0017] As a preferred embodiment of the method for measuring the degree of cell collapse described in the present invention, in which: in this method, the influence of temperature, tissue porosity and electrolyte concentration is taken into account, and correction coefficient a is used for correction, and correction coefficient σ is explained by h and σ′ h The difference between the measured values ​​of

[0018] in,

[0019] A measuring instrument applied to the above-mentioned method for measuring the degree of cell collapse: the measuring instrument comprises a measuring body, a sensor connected to the measuring body, and a plurality of stainless steel probes arranged on the sensor.

[0020] As a preferred solution of the instrument for measuring the degree of cell collapse described in the present invention, the sensor is a two-in-one sensor of conductivity and temperature.

[0021] A preferred embodiment of the above-mentioned cell collapse degree measuring instrument is as follows: the host uses an embedded processor to calculate the sample collapse index, and the host is provided with a display circuit and a display screen to display the measured value and the calculated value.

[0022] Beneficial effects of the present invention: The present invention is based on the electrical impedance characteristics of a living body. Before and after the living body is treated with a high-voltage pulse electric field, a measuring instrument is used to perform low-frequency and high-frequency measurements of the impedance value or conductivity value of the living body.

[0023] Then the cell collapse index is calculated through a calculation formula, providing a quantifiable measure of whether the high-voltage pulse electric field treatment is successful and optimizing the best application parameters of the high-voltage pulse electric field. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

[0025] Figure 1 This is a schematic diagram of the overall structure of an instrument for measuring the degree of cell collapse proposed by the present invention;

[0026] Figure 2 A schematic diagram of a method for measuring the degree of cell collapse proposed by the present invention, in which a cell is equivalent to a series connection and a parallel connection of a resistor R and a capacitor C;

[0027] Figure 3 This is a schematic diagram of a method for measuring the degree of cell collapse proposed by the present invention, in which a cell is equivalent to a breakdown of a capacitor C and a resistance value R drops sharply. DETAILED DESCRIPTION

[0028] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation modes of the present invention are described in detail below with reference to the accompanying drawings.

[0029] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0030] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0031] Secondly, the present invention is described in detail with reference to the schematic diagram. When describing the embodiments of the present invention in detail, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0032] Reference Figure 1-Figure 3, which is an embodiment of the present invention, provides a method and instrument for measuring the degree of cell collapse, the measuring instrument comprising a measuring body 101, a sensor 102 connected to the measuring body, and a plurality of stainless steel probes 103 arranged on the sensor. The sensor 102 is a conductivity and temperature two-in-one sensor, the host 101 uses an embedded processor to calculate the sample collapse index, and the host 101 is provided with a display circuit and a display screen to display the measured value and the calculated value.

[0033] The method for measuring the degree of cell collapse using the above-mentioned measuring instrument is based on the electrical impedance characteristics of the organism. The electrical impedance of the organism refers to the resistance and capacitance characteristics encountered when current flows through the tissue of the organism, which are the ability to resist the flow of current.

[0034] People have observed the electrical resistance characteristics of organisms very early and have also given the reason why organisms produce resistance: when electrolyte ions in extracellular fluid and intracellular fluid move in an electric field, the viscous medium and narrow channels hinder the movement of ions.

[0035] Biological cell membranes have both capacitance and resistance properties. The electrical model of the cell membrane is a leaky capacitor. The lipid bilayer is equivalent to a capacitor, and the protein ion channel is equivalent to a resistor.

[0036] The cell membrane is composed of a lipid bilayer. The inside of the lipid bilayer is filled with dielectrics. The outside and inside of the membrane are filled with extracellular fluid and intracellular fluid, respectively. We regard them as conductive solutions. Therefore, the cell membrane composed of a lipid bilayer is equivalent to a capacitor in terms of electrical properties. The lipid bilayer is the two plates of the capacitor, which are connected to the conductive extracellular fluid and intracellular fluid, respectively, and the middle of the two plates is filled with dielectrics. However, the structure of the cell membrane is not only composed of lipid bilayers, but also of proteins embedded in it. Some of these proteins are so-called "ion channels". Their existence allows ions to be transported across the membrane. In physics terms, the cell membrane capacitor is a "leaky capacitor". Current can pass through the dielectric between the two plates. The leaky capacitor can be represented by an ideal capacitor and a resistor in parallel. The leakage current passes through the capacitor through the resistor.

[0037] The organism is composed of a large number of cells and can be regarded as a collection of many cells. The cell fluid resistance and cell membrane capacitance of the entire cell collection, after very complex series and parallel connections, obtain the equivalent resistance R and equivalent capacitance C representing the entire organism, as shown in Figure 2 shown.

[0038] When low-frequency current flows through an organism that has not been treated with a high-voltage pulse electric field, the impedance is relatively large. This is because the untreated organism exhibits resistance and capacitive reactance characteristics to low-frequency current. The smaller the frequency, the greater the capacitive reactance.

[0039] For organisms that have not been treated with high-voltage pulse electric fields, the impedance decreases when high-frequency current flows through the organisms. This is because the untreated organisms mainly show resistance characteristics to high-frequency currents, and the higher the frequency, the smaller the capacitive reactance.

[0040] When a biological body is treated with a high-voltage pulse electric field, the impedance is small when a low-frequency current or a high-frequency current flows through the biological body. This is because the high-voltage pulse electric field causes electroporation of the cell membrane - the lipid bilayer is destroyed. At this time, the biological body is equivalent to the equivalent capacitor C being broken down, thereby partially or completely losing the capacitance characteristics. Because of the electroporation of the cell membrane - the formation of many ion channels, the equivalent resistance value R of the biological body is sharply reduced, such as Figure 3 shown.

[0041] Before and after the organism is treated with a high-voltage pulse electric field, we use measuring instruments to measure the impedance of the organism at low and high frequencies, and we can calculate the collapse index of the organism's cells.

[0042] Therefore, the impedance or conductivity of untreated materials and pulsed electric field electroporated materials can be measured at low frequencies (1–10kHz) and high frequencies (greater than 50MHz). In power electronics, conductivity is defined as the reciprocal of impedance. Therefore, the cell collapse index Z can be calculated by the following formula.

[0043] in, Where z is the cell collapse index, 0≤z≤1, and the z value varies between 0 for intact cells and 1 for complete collapse; σ' is the conductivity of the sample treated with a pulsed electric field at a low frequency, mS cm -1 ;σ——Conductivity of untreated sample measured at low frequency, mS·cm -1 ; σ h ——Measurement of conductivity of untreated samples at high frequency, mS·cm -1 ;σ′ h ——Measure the conductivity of samples treated with pulsed electric fields at high frequencies, mS·cm -1 .

[0044] Taking potatoes as an example, the specific use of the above instrument is to cut a whole potato in half along the axial or longitudinal direction.

[0045] Half of the potatoes were kept as untreated samples and measured using a measuring instrument with the sensor probe inserted into the center of the potato.

[0046] Press the power button of the host. After the host starts, press the low-frequency measurement button first. The measuring instrument automatically measures and displays the low-frequency conductivity measurement value of the untreated sample, which is 0.237mS / cm. Then press the high-frequency measurement button. The measuring instrument automatically measures and displays the high-frequency conductivity measurement value of the untreated sample, which is 3.624mS / cm.

[0047] The other half of the potato was subjected to high voltage pulse electric field treatment as a high voltage pulse electric field treatment sample and measured using a measuring instrument by inserting a sensor probe into the center of the potato.

[0048] First press the low-frequency measurement key, the measuring instrument automatically measures and displays the low-frequency conductivity measurement value of the sample treated with the pulse electric field, which is 1.540mS / cm. Then press the high-frequency measurement key, the measuring instrument automatically measures and displays the high-frequency conductivity measurement value of the sample treated with the pulse electric field, which is 3.986mS / cm.

[0049] After the above four conductivity measurement values ​​are measured, the host automatically calculates and displays the collapse index Z=0.3497.

[0050] In summary: the present invention is based on the electrical impedance characteristics of a living body. Before and after the living body is treated with a high-voltage pulse electric field, a measuring instrument is used to perform low-frequency and high-frequency measurements of the impedance value or conductivity value of the living body.

[0051] Then the cell collapse index is calculated through a calculation formula, providing a quantifiable measure of whether the high-voltage pulse electric field treatment is successful and optimizing the best application parameters of the high-voltage pulse electric field.

[0052] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for measuring the degree of cell collapse, characterized in that: This method is based on the electrical impedance characteristics of biological organisms. The electrical impedance of biological organisms refers to the resistance and capacitance characteristics encountered when electric current flows through biological tissues, which oppose the flow of electric current. When low-frequency current flows through an organism that has not been treated with a high-voltage pulse electric field, the impedance is relatively large. This is because the untreated organism exhibits resistance and capacitive reactance characteristics to low-frequency current. The smaller the frequency, the greater the capacitive reactance. For organisms that have not been treated with high-voltage pulse electric fields, the impedance decreases when high-frequency current flows through the organisms. This is because the untreated organisms mainly show resistance characteristics to high-frequency currents, and the higher the frequency, the smaller the capacitive reactance. When a biological body is treated with a high-voltage pulse electric field, the impedance is small when a low-frequency current or a high-frequency current flows through the biological body. This is because the high-voltage pulse electric field causes electroporation of the cell membrane - the lipid bilayer is destroyed. At this time, the biological body is equivalent to the equivalent capacitor C being broken down, thereby partially or completely losing the capacitance characteristics. Because of the electroporation of the cell membrane - the formation of many ion channels, the equivalent resistance value R of the biological body is sharply reduced. Before and after the organism is treated with a high-voltage pulse electric field, the impedance of the organism is measured at low and high frequencies using a measuring instrument, and the collapse index of the organism's cells can be calculated. Since conductivity is defined as the inverse of impedance, the cell collapse index can also be calculated by measuring conductivity. The cell collapse index Z can be calculated by the following formula; Where z is the cell collapse index, 0≤z≤1, and the z value varies between 0 for intact cells and 1 for complete collapse; σ is the conductivity of the untreated sample measured at low frequency, mS·cm -1 ; σ'——The conductivity of the sample treated by high voltage pulse electric field measured at low frequency, mS·cm -1 ; σ h ——Measurement of conductivity of untreated samples at high frequency, mS·cm -1 ;σ′ h ——Measure the conductivity of samples treated with high-voltage pulse electric fields at high frequencies, mS·cm -1 .

2. A method for measuring the degree of cell damage according to claim 1, characterized in that: In this method, the low frequency range is 1-10kHz, and the high frequency range is greater than 50MHz.

3. A method for measuring the degree of cell damage according to claim 2, characterized in that: In this method, the effects of temperature, tissue porosity and electrolyte concentration are considered, and the correction factor a is used for correction, and the correction factor σ is used to explain h and σ′ h The difference between the measured values ​​of in, 4. A measuring instrument used in the method for measuring the degree of cell collapse according to any one of claims 1 to 3, characterized in that: The measuring instrument comprises a measuring body (101), a sensor (102) connected to the measuring body, and a plurality of stainless steel probes (103) arranged on the sensor.

5. The instrument for measuring the degree of cell collapse according to claim 4, characterized in that: The sensor (102) is a two-in-one conductivity and temperature sensor.

6. The instrument for measuring the degree of cell collapse according to claim 5, characterized in that: The host (101) uses an embedded processor to calculate the sample collapse index, and the host (101) is provided with a display circuit and a display screen to display the measured value and the calculated value.

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