Reaction of indirect hemagglutination, rland
(Indirect Hemagglutination Test)

The method of detecting antigens and antibodies based on the ability of erythrocytes, on the surface of which antigens or antibodies are pre-adsorbed, agglutinate in the presence of homologous sera or appropriate antigens.

When the antigens are detected, the reaction is denoted by reverse passive hemagglutination - Ropga (Reversed Passive Hemagglutination Test), and when antibodies are detected - Passive Hemagglutination Test (Passive Hemagglutination Test). Ring has been widely used to identify serological markers of infection with the hepatitis B virus, especially HBSAG and antibodies to it.

Currently, various methods of manufacturing erythrocyte diagnosticum, differing in methods for sensitizing erythrocytes (using tannin, glutar aldehyde, chromium chloride, rivochet, etc.), their species affiliation (human, ram, chicken, turkey, etc. ), options for reaction formulation (in microtate tablets, in test tubes, capillaries, etc.) and accounting of results (visual and instrumental). Erythrocyte diagnosticums for the detection of HBSAG and Anti-HBS are issued by many enterprises and firms as in our country and abroad.

More often rf is carried out in microtitation tablets, in which the dilutions of the test serum and control samples are predetermined. After making the erythrocyte diagnosis and incubation, the reaction results are taken into account. Positive are the samples in which the agglutination of red blood cells occurs, having a view of an inverted "umbrella". With a negative reaction - red blood cells settle on the bottom of the wells in the form of a ring or disk.

To confirm the specificity of the results obtained, the reaction is set as a "experimental" erythrocyte diagnosticum (i.e., erythrocytes, sensitized by antigen or antibodies) and with "control" diagnosticum (i.e., erythrocytes are not sensitiveized by antigen or antibodies). The presence of a positive reaction with the "control" diagnostic preparation indicates a false-position reaction. To eliminate nonspecific reactions, the test serum is treated with non-densitimized erythrocytes. The prerequisite for the Ring is the reaction of neutralization, i.e. the confirmation test.

Compared with such methods as RPGs, VEF and RSK, the reaction of indirect hemagglutination has a higher sensitivity (200 to 400 times). So, HBSAG in RPGA can be detected in concentrations of 6-10 ng / ml. The simplicity of reaction and expressivity (20 - 30 minutes) has determined the widespread use of this method in the blood transfusion service to detect HBsAg.

In addition to erythrocyte diagnosticums, diagnostic preparations have been developed for the detection of HBSAG and anti-HBS, the anti-NVS of the IGM class (solid-phase version), HBEAG, hepatitis A virus antigen and antibodies to it, however, all of them did not find applications In practical health care.

Agglutination reaction - ra (from lat. Aggluti- Natio. - bonding) - a simple reaction in which the antibodies of corpuscular antigens (bacteria, erythrocytes or other cells, insoluble particles with antigens adsorbed on them, as well as macromolecular aggregates) occurs. It occurs in the presence of electrolytes, for example, when adding isotonic sodium chloride solution.

Various variants of the reaction of agglutination are used: deployed, indicative, indirect, etc. The reaction of agglutination is manifested by the formation of flakes or sediment

Ra was used for:

definitions of antibodies in the blood serum of patients, for example, during brucellosis (Reaction of Wright, Heddelsson), abdominal title and parathyphones (Voice Reaction) and other infectious diseases;

definitions of the causative agent allocated from the patient;

definitions of blood groups using monoclonal antibodies against alcohols of erythrocytes.

To determine the patient antibodies putunlocked agglutination reaction: Patient add to dilution dilution Diagnosticum (Suspensions of killed microbes) and after a few hours of incubation at 37 ° C note the highest dilution of serum (serum titer) at which agglutination occurred, ie. E. Precipitate formed.

The nature and speed of agglutination depend on the type of antigen and antibodies. An example is the features of the interaction of diagnosticum (O- and I-antigens) with specific antibodies. The reaction of agglutination S. O-diagnosticum (Bacteria killed by heating, preserved thermostable O-antigen) Comes in the form of fine-grained agglutination. The reaction of agglutination with H-diagnosticum (bacteria killed by formalin, which preserved the thermolabile harness H-antigen) is large and flows faster.

If it is necessary to determine the pathogen dedicated from the patient, put approximate reaction of agglutination, Using diagnostic antibodies (agglutinating serum), i.e., serotypes of the pathogen. Approximate reaction is carried out on the glass slide. To a drop of diagnostic agglutinating serum in dilution 1:10 or 1:20, a pure culture of the pathogen dedicated from the patient is added. Next are control: instead of serum, a drop of sodium chloride solution is applied. When a drill with serum and microbes of a flaky precipitate put An unfolded reaction agglutination In test tubes with increasing dilutions of agglutinating serum, to which 2-3 drops of the suspension agent are added. Agglutination is taken into account by the amount of precipitate and the degree of enlightenment of the liquid. The reaction is considered positive if the agglutination is observed in breeding close to the titer of diagnostic serum. At the same time, controls: serum, diluted with isotonic sodium chloride solution, should be transparent, suspension of microbes in the same solution - evenly turbid, without precipitation.

Different related bacteria can be agglutinated by the same diagnostic agglutinating serum, which makes it difficult to identify them. Therefore, use adsorbed agglutinating serums, Of which the cross-reacting antibodies are removed by adsorption by their related bacteria. In such serums, antibodies are preserved, specific only to this bacterium. Obtaining such a: ^ a special monorateborne diagnostic agglutinating sera proposed by A. Castelli (1902).

Reaction of indirect (passive) hemagglutination (RNG, RPGA) is based on the use of erythrocytes with an antigen-adsorbed surface with antigens or antibodies, the interaction of which with appropriate antibodies or blood serum antigens causes bonding and loss of erythrocytes to the bottom of the test tube or cell in The form of a festral sediment (Fig. 13.2). With a negative reaction, the erythrocytes settle ■ "Buttons". Typically, antibodies are detected in rf using antigenic erythrocyte diagnosticum, which is an erythrocyte with adsorbed on the They are antigens. Sometimes anti-erythrocyte diagnostics are used on which antibodies are adsorbed. For example, botulinum toxin can be detected by adding the erythrocytary anticient botulinum diagnosticum to it (such a reaction is called reaction inverse indirect hemagglutination - Ronga). Ring is used to diagnose infectious diseases, determining the gonadotropic hormone in Urine when making pregnancy, to identify increased sensitivity to drugs, hormones and in some other cases.

Cumbsis Reaction

(Coombs Test) - Method for determining the rhesus antibodies on the surface of erythrocytes, which cause the deposition of globulin in serum. This test is used to diagnose hemolytic anemia in babies with rhesus incompatibility, which has the destruction of red blood cells.

Coaggglutination reaction. The causative cells are determined using staphylococci pre-treated with immune diagnostic serum. Staphylococcis containing protein BUT, having an affinity for the Fc-fragment of immunoglobulins non-specifically adsorb anti-microbial antibodies, which is then reacted with the appropriate active centers microbes isolated from patients. As a result of coaggglutination, flakes consisting of staphylococci, antibodies of diagnostic serum and the microbe determined by the microbe are formed.

Gemagglutination braking reaction(RTHA) is based on the blockade, suppressing virus antigens antibodies of immune serum antibodies, as a result of which viruses lose the property agglutinize the red blood cells (Fig. 13.3). RTHA is used to diagnose many viral diseases, whose pathogens (influenza viruses, measles, rubella, tick-borne encephalitis, etc.) can agglutinate red blood cells of various animals.

1. A group of doctors along the WHO doctors arrived in India to identify patients with poliomyelitis and assist in conducting poliomyelitis vanity vaccination. In one of the surveyed villages to doctors brought from a large family of a boy of 6 years, which fell ill 5 days ago. Suddenly the temperature rose, the head was very sick, there was a re-vomiting, pain in his hands and legs. In case of inspection: High temperature, sharp weakness, meningial symptoms, the muscular tone is reduced on the right leg, tendonous reflexes are dramatically weakened, stop hangs. When punctured the spinal channel, the cerebrospinal fluid flowed under increased pressure, the number of lymphocytes was increased, the bacteria were not highlighted. A preliminary diagnosis of the "paralytic form of poliomyelitis" was delivered. How could a boy be infected? How is the specific active polyomyelitis prevention? Is there a danger of infection of other children of this family, what needs to be taken?

Answer: The boy could be infected with fecal-orally through food, water, as well as air-droplet. The basic measure of polyomelitis prevention is immunization of a lively culture vaccine of 3 serotypes of Sabin strains in Russia applied graft from polio For oral administration of the production of the Institute of Poliomyelitis and viral encephalitis. MP Chumakov. Vaccination is a trivalent preparation of attenuated Sabin strains of poliovirus types 1, 2, 3, obtained on a primary culture of kidney cells of African green monkeys. . Children aged 3 months to 6 years are subject to planned vaccines from poliomyelitis. Inoculations are conducted oral polio vaccine for 2 or 4 drops into the vaccine three times in 3, 4, 5 and 6 months, with a booster at 18 three times, 20 months and 14 years. The patient boy must be placed in the hospital, and all other children of this family need to vaccinate a living polio vaccine.

1. The composition and use of a flu vaccine trivalent polymer-subunit liquid (influenza)

This is a molecular vaccine. Ingredients: Surface AG of Flu Viruse of Three Subtypes (A / H1N1, A / H3N2, B). Application: for influenza prevention

Exam ticket number 22.

Table of contents of the topic "Immunomodulators. Immunodiagnostics of infectious diseases.":

Expanded reaction agglutination (R.). To determine AT in the serum of the patient put deployed agglutination reaction (RA). To do this, for a series of serum dilutions, diagnosticum is added to the suspension of killed microorganisms or particles with sorbed hypertension. Maximum breeding giving agglutination AG, called blood serum titer.

Varieties of reaction agglutination (R.) To identify AT - a blood-drip sample on tularevia (with the diagnosis of a drop of blood and the appearance of visible white agglutinates) and the Haddlson reaction on brucellosis (with a drop of serum diagnosticum painted with gentian violet).

Approximate agglutination reaction (RA)

To identify selected microorganisms, approximate RA put on substantive windows. To do this, a culture of the pathogen is added to the drop of standard diagnostic antiserum (in dilution 1:10, 1:20). With a positive result, they put an expulsive reaction with increasing breeding of antiserum.

Reaction They consider positive if agglutination is observed in dilutions close to the titer of diagnostic serum.

OAS. Somatic o-ag Thermostable and withstand boiling for 2 hours. When interacting with AT, fine-grained units are formed.

N-ag. N-ag (flagery) Termolabile and quickly destroyed at 100 ° C, as well as under the action of ethanol. In the reactions with H-anti-seeor after 2 hours, incubations form loose large flakes (formed by bacteria bonding flavored flaking).

VI-A. The abdominal bacteria relative to the thermostable (withstands the temperature of 60-62 ° C for 2 hours); When incubation with VI-antiserum, fine-grained agglutinat is formed.

Reactions direct hemagglutination

The simplest of the like reactions - agglutination Erythrocytes, or hemagglutination used to determine blood groups in the AB0 system. For determining agglutination (or its lack) use standard antisams with anti-a and anti-in-agglutinin. The reaction is called straight, since the AG studied is the natural components of the erythrocytes.

General S. direct hemagglutination Mechanisms has viral hemagglutination. Many viruses are able to spontaneously agglutinate the red blood cells of birds and mammals, their addition to the erythrocyte suspension causes the formation of aggregates of them.

Reaction of direct agglutination of microbes (RA). In this reaction, the antibody (agglutinin) directly agglutinate the corpuscular antigens (aggluthanogen). They are usually represented by the suspension of inactivated microorganisms (microblutination reaction). According to the nature of the generated agglutination, grain and flake agglutination are distinguished. Granular agglutination occurs when gluing microbes containing O-antigen. Bacteria having flagellas (H-antigen) are agglutinized with the formation of large flakes.

To determine the type of microorganisms, standard diagnostic agglutinating serums use. They are obtained by the hyperimmunization of laboratory animals by the suspension of bacteria. The titer of such serum is its largest dilution, in which the distinct agglutination of the corresponding antigen is observed. However, due to the complexity of the antigenic structure of bacteria, agglutination sera contain antibodies not only species specific but also to group antigens and may give the group agglutination from related species of bacteria. Antibody titers to viscific antigens in serum are always higher than to group. To remove group-drug-specific antibodies to serum, microorganisms are sequentially added, which includes group antigens (Castellani method). Such a method is obtained by adsorbed serums that contain antibodies to a certain type of microbe.

Methods of the reaction of agglutination. The most common plate (approximate) and the deployed RA.

Planted RA put on the glass. In this reaction, serums with low dilution or undiluted can be used. Use it as an accelerated method for detecting antibodies or identification of microorganisms. Applied to glass serum drops wherein the loop is made unknown bacteria culture, mixed and observed after 2-3 minutes or grained appearance flocculent agglutination. To control, a drop of a physiological solution is used, in which after making bacteria is observed. When using non-non-serum whey, the reaction on the glass has only an approximate value.

The deployed RA is carried out in test tubes or wells plates. In this case, the diagnostic serum is bred to the titer and the same amounts of antigen are introduced. With a positive result, a loose precipitate is formed at the bottom of the test tube in the form of an "umbrella", with a negative - precipitate in the form of "buttons". Since the titles of group-drug-specific antibodies in serum are significantly lower than the type of cyphic titer, group reactions are observed only in small serum dilutions. If agglutination occurs to the titer or up to half of the serum titer, it is a speciesity.

To determine the original serum antibodies (serological diagnosis), standard microbial diagnostics are used, which contains the suspension of known microbes or their antigens. In this case, you can also put a plate and deployed RA.

Reaction of direct cell agglutination. To determine blood groups, standard donor serums contain known anti-A or anti-in antibodies are used. Reactions put on glass or plates. In the presence of on red blood cells A (2nd blood type), in (3rd blood group) or both antigens (4th blood type), the corresponding serum agglutinate red blood cells. It is also used to compact blood compatibility, when the blood drops of the donor and recipient are mixed and evaluated agglutination.

In clinics use agglutination of leukocytes, platelets and other cells to detect autoantibodies as well as for determination of antigens on these cells.

The hemagglutination reaction is based on the phenomenon of erythrocyte gluing originating under the influence of various factors. Distinguish direct and indirect hemagglutination.
With direct hemagglutination reaction, red blood cells are glued when adsorption of certain antigens on them, such as viruses.

Reaction of indirect (passive) hemagglutination (rland, RPGA)based on using red blood cells (or latex) adsorbed on their surface antigens, or antibodies that interact with the corresponding antibodies or antigens, the sera of patients and causes loss of adhesion of erythrocytes to the bottom of the tubes or cells in the form of scalloped precipitate.

Components.Erythrocytes, horses, rabbits, chickens, mice, humans, and others, which are harvested, processing formalin or glutaraldehyde can be used for Ring. The adsorption capacity of the erythrocytes increases when the tannin or chromium chloride is treated.

Pling antigens can serve as polysaccharide agroorganisms, extracts of bacterial vaccines, ag viruses and rickettsis, as well as other substances.

Erythrocytes, sensitized ag, are called erythrocyte diagnosticum. For the preparation of erythrocyte diagnosticum, rams erythrocytes with high adsorbing activity are most often used.

Application. RNGA is used for diagnosing infectious diseases, determination of gonadotropin in urine when establishing pregnancy for detecting hypersensitivity to drugs, hormones, and in some other cases.

In serological studies, the braking reaction of direct hemagglutination is used, when the virus isolated in a patient is neutralized with specific immune serum, and then combined with erythrocytes. The absence of hemagglutination indicates the compliance of the virus and the immune serum used.

Reaction indirect hemagglutination (passive hemagglutination) observed when erythrocytes pre-treated (sensitized) different antigens, the immune serum is added serum or patient having a corresponding antibody. There is a specific bonding of red blood cells, their passive hemagglutination.

Reaction indirect or passive hemagglutination on sensitivity and specificity superior to other serological methods, and its use in the diagnosis of infections caused by bacteria, rickettsiae, protozoa.

The method of performing the reaction of indirect hemagglutination consists of several stages.

· First, the red blood cells are washed with an isotonic solution of sodium chloride, then if necessary (when using protein antigens), they are treated with a solution of Tanina 1: 20000 and sensitized by soluble antigens.

· After laundering a buffer isotonic solution of sodium chloride, the erythrocytary antigen is ready for use.

· Test serum diluted isotonic sodium chloride solution in the test tubes or plastic plates with special lune, then to each serum dilution was added erythrocytic diagnosticum.

· The results of the reaction of indirect hemagglutination are taken into account by the nature of the sediment of the erythrocytes, which formed at the bottom of the test tube.

· Positive consider the result of the reaction in which the red blood cells are evenly covering all the bottom of the test tubes. With a negative erythrocyte reaction in the form of a small disk or "Buttons" are located in the center of the bottom of the test tube.

· After 2 h incubation at 37 ° C into account the results of evaluating appearance of red blood cells pellet (without shaking) at a negative reaction precipitate appeared as a compact disc or ring at the bottom of the wells with a positive reaction, - the characteristic lace precipitate erythrocytes, a thin film with uneven edges

Coaggglutination reaction.

The basis of this reaction is the unique property of golden staphylococcus, having a protein A composed of its cell wall, to bind to IgG and IgM FC fragments.

At the same time, active centers of antibodies remain free and can interact with specific determinants of antigens. Applied on a glass drop of 2% slurry staphylococci coated with appropriate antibodies, and added a drop of the test bacteria suspension. By matching the antibodies, antibodies after 30-60 ° C occurs clear agglutination of staphylococcal antibodies.

Requirements for immune serum used to sensitize staphylococcal cells and conducting sensitization process. To obtain a coagglutinating reagent, the suspension of staphylococci should be treated with immune serum against the desired antigen. The serum should be taken from the animal, the IgG of which has affinity for the protein A. The greatest affinity for it is the immunoglobulins of man, pigs, dogs and guinea pigs, less - donkey and rabbit, A IgG sheep, horses, rats and mice interact with it very weak .

Apart from the strict specificity to the desired antigen, the serum used in RKOA should not contain antibodies to staphylococci to prevent staphylococcal agglutination reagent due to the influence of specific antigen and antibody, which system IgG - Protein A should be excluded. The control is carried out by mixing on the glass of one droplet of serum and 10% suspension of the staphylococcal reagent. If after 3 ... 5 minutes the flakes of agglutinate are not formed, then serum is considered suitable for the reaction.

If available serum samples to the antigen agglutinate aureus, it is possible to carry out their adsorption suspension staphylococcal cells without protein A (e.g., Wood-46 strains). In this way, antibodies react with staphylococcus due to Fab fragments are removed.

Thus, the serum used to prepare a coagglutinating reagent must meet the following requirements:

• obtained from the animal producer, the IgG of which has affinity for protein A;
• must have specificity in relation to the desired antigen;
• be free from anti-stilococcal antibodies.

· Preparation of diagnosticum. The prepared 10% staphylococcal reagent is connected with an equal volume of immune serum in a certain previously optimal working dilution. The mixture is shaken for 60 minutes at 40 ... 42 ° C in the municipal apparatus at 90 oscillations in 1 min. Then after 15 minutes, the FBI washed twice, resuspend up to 2% of the suspension and can be preserved with sodium dimly (1: 10 000).

The laboratory diagnosis of almost all infectious diseases is based on the detection of patients with antibodies, which are produced on the antigens of the pathogen, the methods of serological reactions. They entered medical practice from the end of the nineteenth - the beginning of the twentieth century.

Science development helped to determine the antigenic structure of microbes and the chemical formulas of their toxins. This made it possible to create not only therapeutic, but also diagnostic serums. They are obtained by introducing weakened pathogens with laboratory animals. After several days of excerpts from the blood of rabbits or mice prepare preparations used to identify microbes or their toxins using serological reactions.

The external manifestation of such a reaction depends on the conditions of its formulation and on the state of antigens in the patient's blood. If the particles of microbes are insoluble, then they are deposited, lysed, bind or immobilized in serum. If antigen is soluble, then the phenomenon of neutralization or precipitation is manifested.

Agglutination reaction (RA)

Serological reaction agglutination is highly specific. It is easy to perform and quite visually to quickly determine the presence of antigens in the serum of the patient. It is used to produce the reaction of Vidal (the diagnosis of abdominal typhoid and paratif) and weagle (raw tit).

It is based on a specific interaction between human antibodies (or agglutinins) and microbial cells (agglututenogen). After their interaction, particles are formed, which fall into the sediment. This is a positive sign. For reaction formulation, live or killed microbial agents, mushrooms, simplest, and somatic cells can be used.

Chemically, the reaction is broken into two stages:

1. Specific antibody compound (AT) with antigens (AG).
2. Non-specific - the deposition of ag-at conglomerates, that is, the formation of agglutinate.

Reaction of indirect agglutination (RPGA)

For its production, purified erythrocytes and red blood tales of man, previously treated with antibodies or antigens (it depends on what is like a laboratory want to find). In some cases, human erythrocytes are treated with immunoglobulins. Serological reactions of erythrocytes are considered to be held if their deposition on the bottom of the test tube occurred. You can talk about a positive reaction when the cells are located in the form of an inverted umbrella, occupying all the bottom. The negative reaction is counted if the erythrocytes died with a column or in the form of an interact in the center of the bottom.

Preventation reaction (RP)

Serological reactions of this type serve to identify extremely small antigens particles. This can be, for example, proteins (or parts of them), connections of proteins with lipids or carbohydrates, parts of bacteria, their toxins.

Serum for reaction is obtained by artificially infected with animals, usually rabbits. In this method, absolutely any precipitating serum can be obtained. The formulation of serological reactions of precipitation is similar by the mechanism of action on the reaction of agglutination. Antibodies contained in serum are connected to antigens into forming large protein molecules that are deposited on the bottom of the test tube or the substrate (gel). This method is considered highly specific and even insignificantly small amounts of substance can detect.

Used to diagnose plague, tularemia, Siberian ulcers, meningitis and other diseases. In addition, involved in forensic medical examination.

in gel

Serological reactions can be carried out not only in the liquid medium, but also in the agar gel. This is called the method of diffuse precipitation. With it, it is studied the composition of complex antigenic mixtures. This method is based on hemotaxis antigens to antibodies and vice versa. In the gel, they move towards each other at different speeds and, meeting, form the line of precipitation. Each line is one set of AG-AT.

Neutralization reaction of antitoxin exotoxin (pH)

Antitoxic serums are able to neutralize the effect of exotoxin, which produce microorganisms. This serological reactions are based on this. Microbiology uses this method for serum titration, toxins and anatoxins, as well as determining their therapeutic activity. The neutralization force of toxin is determined by conventional units - ae.

In addition, due to this reaction, it is possible to determine the species or typical belonging of the exotoxin. This is used in diphtheria, botulism. The study can be carried out both "on the glass" and in the gel.

Lysis Reaction (RL)

Immune serum, which enters the patient's body, has, besides its main function of passive immunity, also lying properties. It can dissolve microbial agents, cellular alien elements and viruses entering the patient's body. Depending on the specificity of the penetration of antibodies, bacterioles, cytolysins, spirochetolysins, hemolysins and others are separated into the serum.

These specific antibodies are called "Complete". It is contained in almost all human body fluids, has a complex protein structure and is extremely sensitive to increasing temperature, shaking, action of acids and direct sunlight. But in the dried state, it is capable of maintaining its lysiring properties to six months.

There are such types of serological reactions of this type:

Bacteriolysis;

Hemolysis.

Bacteriolism is carried out using a patient's blood serum and a specific immune serum with alive microbes. If there is a sufficient number of complement in the blood, the researcher will see lysis bacteria, and the reaction will be considered positive.

The second serological blood reaction lies in the fact that the suspension of the patient's erythrocytes is treated with serum containing hemolysins that are activated only in the presence of a specific compliment. If there is any, then the laboratory manifests the dissolution of red blood cells. This reaction is widely used in modern medicine to determine the complement titer (i.e. its smallest quantity of lysis of erythrocytes) in serum and for setting an analysis of complement binding. This method is carried out serological reaction to syphilis -

Complement Binding Reaction (RSK)

This reaction is used to detect a patient antibody in the blood serum to an infectious agent, as well as to identify the pathogen by its antigenic structure.

Up to this point, we described simple serological reactions. RSK is considered a complex reaction, since it interacts not two, but three elements: antibody, antigen and complement. Its essence lies in the fact that the interaction between the antibody and the antigen occurs only in the presence of compliment proteins, which are adsorbed on the surface of the AG-AT complex.

The antigens themselves, after the complement attachment, are subject to significant changes that show the quality of the reaction. It may be lysis, hemolysis, immobilization, bactericidal or bacteriostatic action.

The reaction itself takes place in two phases:

1. The formation of a complex antigen antibody, which is visually not noticeable to the researcher.
2. Change the antigen under the action of complement. This phase is most often traced by the naked eye. If the visual reaction is not visible, then use an additional indicator system that allows you to identify changes.

Indicator system

This reaction is based on the binding of the complement. In the test tube, an hour after RSK is set to add purified branches and hemolytic serum that does not contain complement. If a unrelated complement remained in the test tube, it will join the AG-AT complex formed between branch cells and hemolynsine, and causes them dissolution. This will mean that RSK is negative. If the erythrocytes remained integer, then, accordingly, the reaction is positive.

Hemagglutination reaction (RGA)

There are two fundamentally different hemagglutination reactions. One of them is serological, it is used to determine blood groups. In this case, red blood cells interact with antibodies.

And the second reaction does not relate to serological, since the red blood tales react with hemagglutinins produced by viruses. Since each pathogen acts only on specific erythrocytes (chicken, lamb, monkey), then this reaction is narrowly specialized.

Understand the positive reaction or negative, it is possible by the location of blood cells at the bottom of the test tube. If their drawing resembles an inverted umbrella, then the desired virus is present in the patient's blood. And if all the erythrocytes have liked the mint of the column, then there are no desired pathogens.

Gemagglutination braking reaction (RTHA)

This is a highly specific reaction that allows you to establish the type of virus type or the presence of specific antibodies in the patient's blood serum.

Its essence is that antibodies added to the test tube with the material under study, prevent the deposition of antigens on red blood cells, thereby stopping hemagglutination. This is a qualitative sign of the presence of specific antigens in the blood to a specific desired virus.

Immunofluorescence reaction (reef)

The reaction is based on the ability to identify the complexes of AG-AT with after their treatment with fluorochromic dyes. This method is easy to appeal, does not require the release of pure culture and takes little time. It is indispensable for rapid diagnosis of infectious diseases.

In practice, these serological reactions are divided into two types: straight and indirect.

Direct reef is produced with an antigen, which is pre-treated with fluorescent serum. And the indirect is that at first the drug is treated with the usual diagnosticum containing antigens to the desired antibodies, and then fluorescent serum is re-applied, which is specific to the proteins of the AG-AT complex, and microbial cells become visible during microscopy.