JP3300493B2 - Method for detecting or measuring the presence of a biologically specific reactive substance - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for detecting or measuring the presence of a biologically specific reactive substance by a biologically specific agglutination reaction on carrier particles. More specifically, by applying an AC voltage to the reaction system in the presence of a salt,
The present invention relates to a method for detecting or measuring the presence of a biologically specific reactive substance more quickly and simply than conventional methods and with high sensitivity.

[0002]

2. Description of the Related Art As a method for detecting or measuring the presence of a biologically specific reactive substance, for example, an enzyme immunoassay,
Radioimmunoassay has been used conventionally. These methods have high sensitivity and high accuracy. However, since reagents are unstable due to the use of enzymes and radiation, and there are regulations on storage and preservation, detailed considerations and techniques are required for measurement, and thus a simpler method has been required. In addition, since these methods require a relatively long time for measurement, it is difficult to cope with them in an emergency test, and high-sensitivity and quick methods have been actively studied.

[0003] Since 1970, various optical analysis methods for measuring specific agglutination on carriers such as latex and blood cells have been developed. The reaction temperature in these analysis systems is generally in the range of 37 to 45 ° C., and a specific agglutination reaction proceeds by stirring with a stirring blade or the like. At this time, the time required for the measurement (reaction) is about 10 to 20 minutes, which is quicker than the enzyme immunoassay and the radioimmunoassay, but the measurement sensitivity and the measurement range are said to be inferior to the above-mentioned assay. I have.

[0004] It is known to apply a DC pulse voltage to a reaction system in order to promote an immunological agglutination reaction and to facilitate detection of formed aggregates. For example, JP
9-173761 (Suzuki et al.) And Ana by Matsuoka et al.
l. Chem. , 57, 1998-2002 (19
85), a distilled water suspension of Candida albicans and a distilled aqueous solution of antibody were injected into a cuvette equipped with electrodes and mixed, and then pulse height was 100 V (electric field intensity was 100 V / m).
It is described that by applying a DC pulse voltage of m) to accelerate the agglutination reaction, the agglutination rate becomes about 50% in a reaction time of about 5 minutes.

[0005] Also, Biosensors, by Tamiya et al.
3 (3), pp. 139-146 (1988) describe that a suspension of an antibody against human immunoglobulin G bound to latex particles in distilled water and a distilled aqueous solution of human immunoglobulin G are mixed in a cuvette equipped with electrodes. , Pulse height 20
It is described that a 50% cohesion degree was obtained 10 minutes after applying a DC pulse voltage of 0 V (electric field strength 200 V / mm).

[0006]

However, in the method of applying a DC pulse voltage, the promotion of the agglutination reaction is still insufficient, so that the measurement time, the measurement sensitivity and the measurement accuracy are not sufficiently satisfactory. Further, the above-described method of applying a direct current pulse has a disadvantage that electrolysis of the reaction solution easily occurs, and it has been necessary to minimize the salt concentration of the reaction solution in order to prevent the electrolysis from occurring. Therefore, it cannot be said that a simple method such as a pretreatment for adjusting the salt concentration in the reaction system is required for a measurement sample, particularly a biological sample.

Accordingly, an object of the present invention is to solve the above-mentioned problems and to detect or measure the presence of a biologically-specific reactive substance with higher sensitivity and simpler and faster than conventional measuring methods. It is in.

[0008]

Means for Solving the Problems The present inventors have found that when detecting or measuring the presence of a biologically specific reactive substance by a biologically specific agglutination reaction on carrier particles, the reaction system is used. By applying the AC voltage, the electrolysis of the reaction solution can be significantly suppressed as compared with the case of applying the DC pulse voltage, and therefore, a salt having an action of promoting a biological-specific agglutination reaction is present in the reaction system. I found that I can do it. The present invention has been achieved based on such findings.

That is, the present invention relates to a method for detecting or measuring the presence of a biologically specific reactive substance by a biologically specific agglutination reaction on carrier particles, wherein the method comprises the steps of: An AC voltage is applied to the reaction system so as to have an electric field strength of 5 to 50 V / mm.

It is known that carrier particles are arranged linearly when an electric field is applied (this phenomenon is called pearl chaining), and when the electric field is stopped, the carrier particles arranged linearly are redispersed. . If a biologically specific reactive substance is present during the pearl-chaining, the carrier does not redisperse even after the electric field is stopped, and the presence of the pearl-chained carrier is still recognized. Therefore, the presence of the biospecific reactive substance can be detected or measured by measuring the aggregated particles that do not redisperse even after the electric field is stopped, that is, participate in the biospecific agglutination reaction.

In order to achieve the object of the present invention, (1) promotion of pearl chaining of a carrier when an electric field is applied, (2)
After stopping the electric field, promote the redispersion of the carrier not involved in the biological-specific agglutination reaction. (3) After stopping the electric field, re-establishing the pearl-chained carrier involved in the biological-specific agglutination reaction Prevention and suppression of dispersion and (4) suppression of electrolysis of a reaction solution containing a salt when an electric field is applied are important. The present invention makes it possible to detect or measure the presence of a biologically specific reactive substance more easily and more quickly and more sensitively than conventional measurement methods by satisfying all of the above conditions (1) to (4). You can.

In the present invention, the term "biospecific agglutination reaction" refers to a reaction in which a substance reacts only with a specific substance or a very small number of specific substance groups and aggregates on carrier particles. And may include a wide range of reactions. For example, a reaction between an antigen or a hapten and an antibody (immune reaction),
Hybridization between complementary nucleic acids, reaction between lectin and its receptor and the like can be mentioned.

The "biologically specific reactive substance" in the present invention can be selected from substances which undergo the above-mentioned biologically specific agglutination reaction and can be measured by an agglutination method using latex, blood cells and the like as a carrier. For example, AFP, CEA, CA1
9-9, tumor markers such as hCG, ferritin, coagulation and fibril markers such as protein C, protein S, ATIII, FDP, and D-dimer; infectious disease markers such as CRP, ASO, HBs antigen, HBs antibody, and TSH. , Prolactin, hormones such as insulin, IgG, IgE, I
Examples include immunoglobulins and complement components such as gA, C3 and C4, tissue components such as myoglobin and myosin, and nucleic acids such as DNA.

In the present invention, it is essential that the voltage applied is an AC voltage. By using AC voltage,
Electrolysis of the reaction solution is less likely to occur than in the case of the DC pulse voltage, and thus the presence of a salt in the reaction solution can be tolerated. As described below, the presence of the salt promotes the biospecific agglutination. In addition, since the presence of a salt is allowed, the measurement can be performed without pretreating a biological sample or the like.

In the present invention, the AC voltage indicates a peak value voltage.

The waveform of the AC voltage of the present invention may be a continuous wave or a pulse wave, and may be of any shape, but is preferably a square wave, a rectangular wave, a sine wave, a triangular wave, or the like. Most preferably, it is a square wave.

The AC voltage of the present invention has an electric field strength of 5 to 50 V.
/ Mm is indispensable. When the electric field strength is less than 5 V / mm, pearl chains of the carrier hardly occur, and thus the promotion of the aggregation reaction becomes insufficient. If the electric field strength is larger than 50 V / mm, electrolysis of the reaction solution is likely to occur, and it becomes difficult to measure the agglutination reaction.
The AC voltage is applied so as to obtain an electric field strength of preferably 10 to 30 V / mm, and most preferably 10 to 20 V / mm.

The alternating current frequency of the present invention does not greatly affect the speed of the biological-specific agglutination reaction within the range studied, but is preferably a frequency of 10 KHz to 10 MHz, more preferably a frequency of 50 KHz to 1 MHz.

The carrier particles of the present invention include latex particles, bentonite, kaolin, colloidal gold, red blood cells, gelatin, liposomes and the like. As the latex particles, those generally used in an agglutination reaction can be used. Polystyrene-based latex, polyvinyltoluene-based latex, polymethacrylate-based latex, etc., and functional group monomers (-COOH, -O
H, -NH _2, may be of the type -SO _3, etc.) is introduced by copolymerizing. Preferred carriers are latex particles.

The higher the concentration of the carrier particles in the reaction system, the easier the pearl chains are formed, so that the agglutination reaction is promoted. In addition, the higher the concentration of the carrier particles, the greater the degree of aggregation of the carrier particles when redispersed when no biologically specific reactive substance is present. The concentration of the carrier particles in the reaction system is, for example, in the case of latex particles, preferably 0.01 to 1% by weight, more preferably 0.025 to 0.
It is 5% by weight, most preferably 0.05-0.1% by weight.

The average particle size of the carrier particles is preferably 0.5 to 10 μm in the case of latex particles, for example. The average particle size is O. If it is 5 μm or less or 10 μm or more, pearl chains are not easily formed, which is not preferable. The average particle size of the carrier particles is, for example, preferably 1 in the case of latex particles.
５5 μm, most preferably 2-3 μm.

In the present invention, it is essential that the salt is present in the reaction system at a relatively high concentration of 10 mM or more. 10m
At a salt concentration of M or less, the promotion of the biospecific agglutination is not sufficient, and the object of the present invention cannot be achieved. If the salt is present in the reaction system at a concentration of 600 mM or more, electrolysis of the reaction solution is likely to occur, which is not preferable. A more preferred salt concentration is 10 to 300 mM, and a most preferred salt concentration is 25 to 150 mM. When a biological sample or the like contains the salt referred to in the present invention, the reagent is prepared so that the salt concentration in the reaction system falls within the above range.

When a direct current pulse is used, electrolysis occurs even in a reaction solution having a salt concentration of about 6 mM. Therefore, it is difficult to measure a biospecific agglutination reaction in the presence of a salt.

The salt in the present invention can be selected from those that promote a biospecific agglutination reaction. Examples include, but are not limited to, sodium chloride, potassium chloride, sodium nitrate, potassium nitrate, and ammonium chloride. Preferred salts are, for example, sodium chloride,
Potassium chloride, ammonium chloride, etc., having a molar electric conductivity of 10 mM, 100 cm ^{2 in} an aqueous solution at 25 ° C.
/ (Ω · mol) or more.

A preferred embodiment of the present invention includes the method wherein the biologically specific reactive substance is an antigen and / or an antibody. Examples of the antigen / antibody include those described above, and preferably include myoglobin / anti-myoglobin antibody, human AFP / human AFP antibody, and the like.

A further preferred embodiment of the present invention includes the method wherein the carrier particles are antibody-sensitized latex particles and the biologically specific reactive substance is an antigen.
The sensitization of the latex particles with the antibody can be performed, for example, by adsorbing or binding the antibody to the latex particles by a conventionally known method. As antigens and antibodies,
Examples of the combination described above can be given.

[0027]

EXAMPLES The present invention will be described in detail below with reference to examples and comparative examples, but these do not limit the present invention.

Example 1 Application time and redispersion time (1) Preparation of anti-myoglobin antibody-sensitized latex reagent 0.375 mg of anti-myoglobin antibody (Organon)
Teknika N .; V. In 8 ml of glycine buffer (0.1 M glycine, 50 mM sodium chloride,
Containing 0.05% sodium azide, abbreviated as GBS hereinafter)
And 2 ml of 2.16 μm fluorescently labeled latex (Polyscience, 2.5% solids suspension) was added and stirred at room temperature for 2 hours. The sensitized latex was centrifuged to remove the supernatant. did. The precipitate was subjected to 25 m of a 0.2% bovine serum albumin glycine buffer solution (0.2% BSA-GBS).
1 to prepare an anti-myoglobin antibody-sensitized latex reagent.

(2) Measuring Apparatus The biological specific agglutination was measured using the apparatus shown in FIG. Electrodes 3 and 4 sandwiched between slide glasses 1 and 2 (electrode thickness: 0.02 mm, distance between electrodes: 0.5 mm)
AC voltage is applied by an AC power supply. The aggregation state of the carrier is measured by an image processing device including a fluorescence microscope 7, a CCD camera 8, an image processing board 9, and a personal computer 10.

(3) Measurement method 0.5% bovine serum albumin in glycine buffer solution (0.
(5% BSA-GBS) was used to dilute the standard myoglobin to prepare samples having concentrations of 0 and 100 ng / ml. 10 μl of these specimens and 10 μl of the anti-myoglobin antibody-sensitized latex reagent described above were mixed on a slide glass, and an AC voltage (square wave) having a frequency of 100 KHz was applied at an electric field intensity of 20 V / mm for 1 minute using the above-described apparatus. To form a pearl chain. The concentration of latex particles in the reaction system was 0.1% by weight. Immediately after the application for 1 minute, the power is turned off and the mixture is left for 1 to 2 minutes to redisperse latex particles not involved in the biospecific agglutination reaction. The degree of aggregation (AR) was determined by the following equation. Then, the average of five screens was taken as the cohesion degree, and the reactivity was measured.

AR = (number of particles agglomerated into two or more) /
(Total number of particles) × 100 (%) (4) Results FIG. 2 shows the change over time in the degree of aggregation. A sample having a myoglobin concentration of 100 ng / ml exhibits an agglutination degree (AR) of about 90% when an AC voltage is applied for 1 minute, and an agglutination degree of about 80% even when the power is turned off and redispersed for 1 to 2 minutes. Was almost constant. On the other hand, the myoglobin concentration was 0 ng /
The ml sample showed about 90% agglomeration degree (AR) by applying an AC voltage for 1 minute.
By redispersing for 2 minutes, the degree of aggregation became about 20%. This means that the carrier is sufficiently aggregated by applying an AC voltage for 1 minute, and the power is turned off immediately after the application and left for 1 to 2 minutes, so that latex particles not participating in the biological-specific agglutination reaction are reduced. Although almost completely re-dispersed, latex particles involved in the biospecific agglutination reaction show little re-dispersion.

Example 2 Influence of applied voltage (1) Preparation of anti-myoglobin antibody-sensitized latex reagent In the same manner as in Example 1, an anti-myoglobin antibody-sensitized latex reagent was prepared.

(2) Measuring Apparatus The biological specific agglutination was measured using the apparatus shown in FIG.

(3) Measuring Method An AC voltage (square wave) of 100 KHz was applied for 1 minute so that the electric field strength shown in Table 1 was obtained to form a pearl chain. Immediately after the application for 1 minute, the power was turned off and the apparatus was left for 1 minute to measure the agglomeration degree (AR) of the latex particles in the same manner as in Example 1.

(4) Results From the results in Table 1, the electric field strength was 5 to 50 V / mm,
More preferably 10 to 30 V / mm, most preferably 1 to 30 V / mm
It turns out that it is 0-20V / mm.

[0036]

[Table 1]

When a DC pulse (frequency: 8 KHz, pulse width: 20 μsec, electric field strength: 20 V / mm) was applied, the reaction solution immediately electrolyzed, and the degree of aggregation could not be measured.

Example 3 Influence of AC Frequency An AC voltage (square wave) having a frequency of 10 KHz to 10 MHz was applied so that the electric field strength became 20 V / mm.
The degree of aggregation was measured in the same manner as described above. From the results shown in Table 2, it can be seen that the AC frequency does not significantly affect the biological-specific agglutination reaction between 10 KHz and 10 MHz.

[0039]

[Table 2]

Example 4 Influence of the concentration of latex particles The concentration of latex particles was 0.025 to
An anti-myoglobin antibody-sensitized latex reagent was prepared in the same manner as in Example 1 so as to be 0.5% by weight. An AC voltage (frequency 100 KHz, electric field strength 20 V / mm, square wave) was applied, and the degree of aggregation was measured in the same manner as in Example 2. Table 3 shows the results.

[0041]

[Table 3]

Example 5 Influence of Particle Size of Latex Particles Latex particles having an average particle size shown in Table 4 below were used, and the concentration of latex particles was adjusted to the reaction system so that the concentration shown in Table 4 was obtained. A myoglobin antibody-sensitized latex reagent was prepared in the same manner as in Example 1. An AC voltage (frequency 100 KHz, electric field strength 20 V / mm, square wave) was applied to form pearl chains of latex particles in the same manner as in Example 1, and the presence or absence of pearl chains was observed. From the results shown in Table 4, it can be seen that the average particle size of the latex particles is 0.5 to 10 μm, preferably 1 to 5 μm, and more preferably 2 to 3 μm. AC voltage of sine wave and triangle wave (frequency 100KHz, electric field strength 20V
/ Mm), the same result was obtained.

[0043]

[Table 4]

Example 6 Influence of Salt Concentration (Part 1) (1) Preparation of Anti-Myoglobin Antibody-Sensitized Latex Reagent The anti-myoglobin antibody-sensitized latex reagent prepared in the same manner as in Example 1 was centrifuged to obtain a supernatant. After removal of the precipitate, the precipitate was suspended in purified water. The above operation of centrifugation and suspension in purified water was further repeated 5 times on the obtained suspension to perform a desalting treatment to obtain a suspension having a latex concentration of 1%.

(2) Measuring Apparatus Using the apparatus shown in FIG. 1, formation of pearl chains and electrolysis of the reaction solution were observed.

(3) Experimental method Aqueous sodium chloride solution (600, 300, 150, 7)
5, 50, 25, 12.5, 6.25, 3.2 and 0 m
M) and the desalted anti-myoglobin antibody-sensitized latex reagent prepared in (1) were mixed at a ratio of 9: 1 to give a latex concentration of 0.1%. An AC voltage (frequency 100 KHz, square wave) was applied so as to have an electric field intensity of 0 to 100 V / mm, and formation of pearl chains and electrolysis of the reaction solution were observed.

(4) Results As shown in Table 5, formation of pearl chains was observed at an electric field strength of about 10 V / mm when the concentration of sodium chloride in the reaction system was 0 to 600 mM. In the electrolysis of the reaction solution, the concentration of sodium chloride in the reaction system was 600 m.
In the case of M, it was observed at an electric field strength of 13 V / mm, and when the concentration of sodium chloride in the reaction system was 300 mM or less, it was observed at an electric field strength of about 20 to 30 V / mm.

[0048]

[Table 5]

Comparative Example 1 DC pulse (frequency 8 KHz, pulse width 20 μsec,
(20 V / mm) was applied in the same manner. When the concentration of sodium chloride in the reaction system was 6.25 mM or more, electrolysis occurred, and the formation of pearl chains was not observed.

Example 7 Influence of Salt Concentration (Part 2) An anti-myoglobin antibody-sensitized latex reagent was prepared in the same manner as in Example 1 using GBS so that sodium chloride at a concentration shown in Table 6 below was included in the reaction system. Prepared. An AC voltage (frequency: 100 KHz, electric field strength: 20 V / mm, square wave) was applied, and the degree of aggregation was measured in the same manner as in Example 2. From the results shown in Table 6, the concentration of sodium chloride was 1
It can be seen that the concentration is 0 mM or more, preferably 25 to 150 mM.

[0051]

[Table 6]

Example 8 (1) Preparation of anti-myoglobin-sensitized latex reagent Prepared in the same manner as in Example 1.

(2) Measuring Apparatus The biological specific agglutination was measured using the apparatus shown in FIG.

(3) Measurement method 0.5% bovine serum albumin in glycine buffer solution (0.
5% BSA-GBS) to dilute standard myoglobin to a concentration of 0, 1.0, 2.5, 5.0, 10, 25,
Samples at 50, 100, and 250 ng / ml were prepared. 10 μl of these specimens and 10 μl of the above-mentioned anti-myoglobin-sensitized latex reagent were mixed on a slide glass, and an AC voltage (square wave) having a frequency of 100 KHz was applied to the electric field strength of 20 V / mm using the above-mentioned apparatus. By applying for 0.5, 1.0 and 1.5 minutes, a pearl chain was formed. Immediately after this application, turn off the power and
After allowing the mixture to stand for a minute to redisperse latex particles not involved in the immune reaction, the degree of aggregation (AR) was measured.

(4) Results From the results shown in FIG. 3, it can be seen that the agglomeration degree is almost sufficient when the application time is 0.5 minutes, and the agglomeration degree is almost equilibrium in 1.0 to 1.5 minutes. This indicates that the present invention can detect or measure the presence of a biologically specific reactive substance in a very short time and with high accuracy.

Example 9 The preparation and measurement apparatus of the anti-myoglobin antibody-sensitized latex reagent were the same as in Example 1. Standard myoglobin was diluted with 0.5% bovine serum albumin in glycine buffer (0.5% BSA-GBS) to a concentration of 0,0,0.
Samples of 1, 1, 2.5, 5, 10, 25, 50, 100, and 250 ng / ml were prepared. These samples were treated in the same manner as in Example 2 to determine the degree of aggregation (AR) of latex particles.
Was measured.

FIG. 4 shows the results when the application time and the leaving time of the AC voltage were 1 minute and 30 seconds, respectively.

Comparative Example 2 Each 50 μl of each sample of Example 9 and the anti-myoglobin antibody-sensitized latex reagent were placed in a reaction tube, and were placed at 37 ° C. for 2 hours.
Incubated for 0 minutes. 20 μl of this reaction solution
Was placed on a slide glass, and the degree of aggregation was measured in the same manner as in Example 1. The results are shown in FIG.

FIG. 4 shows that the present invention uses the conventional method (37 ° C.).
It is found that the measurement can be performed in a very short time and with high sensitivity as compared with the case where an incubation time of 10 to 20 minutes is required.

Example 10 (1) Preparation of anti-human AFP antibody-sensitized latex reagent An anti-human AFP antibody-sensitized latex reagent was prepared in the same manner as in Example 1 using an anti-human AFP antibody (manufactured by Doto Chemical Co., Ltd.). Prepared.

(2) Measuring device The agglutination reaction was measured using the device shown in FIG.

(3) Measurement method 0.5% bovine serum albumin in glycine buffer solution (0.
5% BSA-GBS) to dilute the standard AFP,
Concentration 0, 0.1, 0.5, 1.0, 2.5, 5.0, 1
Samples at 0, 50, 100, 500 and 1000 ng / ml were prepared. 10 μl of these specimens and 10 μl of the anti-human AFP antibody-sensitized latex reagent described above were mixed on a slide glass, and a frequency of 100
An alternating voltage (square wave) of KHz was applied at an electric field intensity of 16 V / mm for 40 seconds to form a pearl chain. The concentration of latex particles in the reaction system was 0.1% by weight. 4
Immediately after the application for 0 seconds, the power was turned off and left for 40 seconds to redisperse latex particles not involved in the biospecific agglutination reaction, and then the degree of agglutination (AR) was measured.

(4) Results The results are shown in FIG.

Comparative Example 3 Each sample of Example 10 and an anti-human AFP antibody-sensitized latex reagent were placed in a reaction tube in an amount of 50 μl each.
Incubated for 0 minutes. 20 μl of this reaction solution
Was placed on a slide glass, and the degree of aggregation was measured in the same manner as in Comparative Example 1. The results are shown in FIG.

FIG. 5 shows that the present invention uses the conventional method (37 ° C.).
It is found that the measurement can be performed in a very short time and with high sensitivity as compared with the case where an incubation time of 10 to 20 minutes is required.

[0066]

According to the present invention, it is possible to detect or measure the presence of a biologically-specific reactive substance more easily and more quickly and more sensitively than conventional methods.

[Brief description of the drawings]

FIG. 1 shows a schematic diagram of an apparatus for detecting or measuring the presence of a biologically specific reactive substance used in the present invention.
(A) is an overall view, and (B) is a cross-sectional view of a combination portion of a slide glass and an electrode.

FIG. 2 is a graph showing a change in a cohesion degree when an AC voltage is applied and a change in a cohesion degree when the application of the AC voltage is stopped and re-dispersed.

FIG. 3 is a graph showing the relationship between myoglobin concentration, application time of AC voltage, and degree of aggregation.

FIG. 4 is a graph showing the relationship between myoglobin concentration and the degree of aggregation.

FIG. 5 is a graph showing the relationship between the concentration of human AFP and the degree of aggregation.

[Explanation of symbols]

 1, 2: slide glass 3, 4: electrode 5: AC power supply 6: oscilloscope 7: fluorescence microscope 8: CCD camera 9: image processing board 10: personal computer

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-66224 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01N 33/543 581 BIOSIS (DIALOG) JICST file (JOIS)

Claims (7)

(57) [Claims] 1. Biologically specific agglutination reaction on carrier particles
Detection or measurement of the presence of biologically specific
AC voltage so that the carrier particles form a pearl chain.
The above method, wherein the method is applied to the reaction system. 2. An alternating current having a frequency of 10 kHz to 10 MHz.
The method of claim 1, wherein the method is a number. 3. In the coexistence of a salt of 10 mM or more, 10 to 5
An AC voltage is applied to the reaction so that the critical strength becomes 0 V / mm.
3. The method according to claim 1, wherein the voltage is applied to a system.
Method. 4. A biospecific agglutination reaction on carrier particles
Detection or measurement of the presence of biologically specific
A 10 kHz to 10 MHz in the presence of a salt of 10 mM or more.
Applying an alternating voltage having a frequency of
Said method. 5. In the presence of 10 to 300 mM salt.
The method according to any one of claims 1 to 4, wherein
Law. 6. The carrier particles have an average particle size of 0.5 to 10 μm.
m.
The described method. 7. The method according to claim 1, wherein the concentration of the carrier particles in the reaction system is 0.01%.
7 to 1% by weight.
The method according to any of the above.