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The portion of the antibody molecule that binds to the EPITOPE is called as PARATOPE. Epitope and paratope DETERMINE the specificity of immunological reactions.

The portion of the antibody molecule that binds to the epitope is called as paratope. Epitope and paratope determine the specificity of immunological reactions.

The smallest unit of antigenesity is known as ANTIGENIC determinant or epitope. The part of the antigen at which the antibody REACTS is known as epitope or antigenic determinant.

It is a small area possessing specific chemical structure and stereo CONFIGURATION on the antigen capable of sensitizing on immuno SITE and of reacting with its complimentary site on the specific antibody.

The smallest unit of antigenesity is known as antigenic determinant or epitope. The part of the antigen at which the antibody reacts is known as epitope or antigenic determinant.

It is a small area possessing specific chemical structure and stereo configuration on the antigen capable of sensitizing on immuno site and of reacting with its complimentary site on the specific antibody.

In this method, both antigens and antibodies diffuse radically from wells towards each other by establishing a concentration gradient. As equivalence is reached, a visible line of precipitation is observed.

The PATTERNS of precipitin lines that are formed when two DIFFERENT antigens are placed in adjacent wells indicate whether they share any common epitope or not.

IDENTITY occurs when two antigens share identical epitopes; hence, the line of precipitation formed by them will fuse to give SINGLE curve line of identity.

Nonidentity occurs when two antigens are unrelated. The antiserum form independent precipitin lines that cross each other.

PARTIAL identity occurs when two antigens share common epitope. The antiserum forms line of identity with the common epitope and a curved spur with the unique epitope.

In this method, both antigens and antibodies diffuse radically from wells towards each other by establishing a concentration gradient. As equivalence is reached, a visible line of precipitation is observed.

The patterns of precipitin lines that are formed when two different antigens are placed in adjacent wells indicate whether they share any common epitope or not.

Identity occurs when two antigens share identical epitopes; hence, the line of precipitation formed by them will fuse to give single curve line of identity.

Nonidentity occurs when two antigens are unrelated. The antiserum form independent precipitin lines that cross each other.

Partial identity occurs when two antigens share common epitope. The antiserum forms line of identity with the common epitope and a curved spur with the unique epitope.

This METHOD cannot the ANTIGENS present in concentration below 510 MICRO grams/ml.

This method cannot the antigens present in concentration below 510 micro grams/ml.

It is USED to qualitate the ANTIGEN. Suitable dilution of antiserum is incorporated in the agar gel. Antigen is added to the wells cut on the surface of the gel. As the antigen diffuses into the agar region, equivalence is established and ring of PRECIPITATION is formed. The area of precipitin ring is directly proportional to the concentration of antigen. By COMPARING the area of precipitin with a standard curve obtained by measuring the precipitin area of known concentration of antigen, the concentration of antigen in the given sample can be determined.

It is used to qualitate the antigen. Suitable dilution of antiserum is incorporated in the agar gel. Antigen is added to the wells cut on the surface of the gel. As the antigen diffuses into the agar region, equivalence is established and ring of precipitation is formed. The area of precipitin ring is directly proportional to the concentration of antigen. By comparing the area of precipitin with a standard curve obtained by measuring the precipitin area of known concentration of antigen, the concentration of antigen in the given sample can be determined.

• Radial IMMUNO DIFFUSION method and
• DOUBLE immuno diffusion in two dimensions

These reactions can be USED to determine RELATIVE concentrations of ANTIGENS and antibodies to compare antigens and to determine the relative purity of an antigen. They are mainly preformed in 1% agarose GELS.

These reactions can be used to determine relative concentrations of antigens and antibodies to compare antigens and to determine the relative purity of an antigen. They are mainly preformed in 1% agarose gels.

1. Precipitation REACTION is the basic reaction for a number of techniques.
2. It is less sensitive for detecting antibodies.
3. Precipitation REACTIONS in gels have several advantages RATHER than in liquid MEDIUM.
4. They have forensic application in identification of blood and seminal stains.

In this, RATIO of antigenantibody is SEEN optimal which results in large multimolecular LATTICE, hence maximum precipitation is observed.

In this, ratio of antigenantibody is seen optimal which results in large multimolecular lattice, hence maximum precipitation is observed.

In this, the first available ANTIGEN is COMPLETELY filled by antibody molecules. Hence, no ANTIGENIC DETERMINANT is left out FREE. Unreacted antibody is seen in large amount, hence poor lattice formation.

In this, the first available antigen is completely filled by antibody molecules. Hence, no antigenic determinant is left out free. Unreacted antibody is seen in large amount, hence poor lattice formation.

The three DISTINCT phases are

• Ascending part called ‘zone of antibody EXCESS’.
• A peak called ‘zone of equivalence’.
• A descending part called ‘zone of ANTIGEN excess’.

The three distinct phases are

Marrak proposed the LATTICE hypothesis to explain the mechanism of precipitation.

The amount of PRECIPITATE formed is greatly influenced by relative PROPORTIONS of ANTIGENS and antibodies.

The valency of antigens is multivalent.

When antigenantibody is in optimal CONCENTRATION, the precipitation is complete. So that, large lattice is formed.

Marrak proposed the lattice hypothesis to explain the mechanism of precipitation.

The amount of precipitate formed is greatly influenced by relative proportions of antigens and antibodies.

The valency of antigens is multivalent.

When antigenantibody is in optimal concentration, the precipitation is complete. So that, large lattice is formed.

When a soluble ANTIGEN COMBINES with corresponding antibody in the presence of electrolyte at a SUITABLE temperature and PH, the antigenantibody complex forms an insoluble precipitate Antibodies that form precipitate ate called PRECIPITANTS.

When a soluble antigen combines with corresponding antibody in the presence of electrolyte at a suitable temperature and pH, the antigenantibody complex forms an insoluble precipitate Antibodies that form precipitate ate called precipitants.

It is broadly classified into FIVE.

1. PRECIPITATION
2. Agglutination
3. COMPLEMENT fixation
4. IMMUNOASSAY using LABELED reagents
5. Immunohistrochemistry (Immunoflourescence)

It is broadly classified into five.

The GLYCOLIPID antigens are present in most tissues of guinea pigs but not in the RBC. They are found in GASTROINTESTINAL MUCOSA in some people. This horseman ANTIGEN will not induce antibody formation.

The glycolipid antigens are present in most tissues of guinea pigs but not in the RBC. They are found in gastrointestinal mucosa in some people. This horseman antigen will not induce antibody formation.

Heterophile antigens are POLYSACCHARIDES, which are STRUCTURALLY similar because of their LIMITED COMPLEXITY. They are derived from members of widely separated TAXONOMIC groups.

Heterophile antigens are polysaccharides, which are structurally similar because of their limited complexity. They are derived from members of widely separated taxonomic groups.

Immuno fluorescence is divided into 2 TYPES

1. DIRECT immuno fluorescence
2. INDIRECT immuno fluorescence

Immuno fluorescence is divided into 2 types

The most COMMONLY USED fluorescent dyes are FLUORESCIN or RHODAMINE. Both dyes can be conjugated to Fc region of antibody without affecting the specificity of the antigen.

The most commonly used fluorescent dyes are fluorescin or rhodamine. Both dyes can be conjugated to Fc region of antibody without affecting the specificity of the antigen.

Fluorescence is the PROPERTY of absorbing light ray of particular WAVELENGTH and EMITTING rays in DIFFERENT wavelength.

Antigens that are bound to cells or tissue sections can be visualized by tugging the antibody MOLECULE with a fluorescent dye or fluorochrome.

Fluorescence is the property of absorbing light ray of particular wavelength and emitting rays in different wavelength.

Antigens that are bound to cells or tissue sections can be visualized by tugging the antibody molecule with a fluorescent dye or fluorochrome.

This technique is APPLIED to DETECT the ANTIBODY against hepatitisB and to detect antibodies against SLE (systemic leupus erythromotosis) and used to detect SPECIFIC antigen foemeningo coccus in cerebrospinal FLUID.

This technique is applied to detect the antibody against hepatitisB and to detect antibodies against SLE (systemic leupus erythromotosis) and used to detect specific antigen foemeningo coccus in cerebrospinal fluid.

This TECHNIQUE involves the simultaneous ELECTROPHORESIS of ANTIGEN and antibody in the gel in the opposite direction resulting in PRECIPITATION of point where there is optimum concentration of antigenantibody.

This method produces visible precipitin with in 30 minutes and is 10 times more sensitive than the STANDARD double diffusion technique.

This technique involves the simultaneous electrophoresis of antigen and antibody in the gel in the opposite direction resulting in precipitation of point where there is optimum concentration of antigenantibody.

This method produces visible precipitin with in 30 minutes and is 10 times more sensitive than the standard double diffusion technique.

1. This TECHNIQUE is useful for testing normal and abnormal proteins in serum and urine.
2. It is useful to determine whether a PATIENT produces abnormally a LOW amount of one or more proteins.
3. It is also USED if a patient over produces some serum proteins.

In PAPER electrophoresis, SERUM proteins can be separated into 5 DIFFERENT bands but the same protein USING immuno electrophoresis can be separated into 30 different proteins.

In paper electrophoresis, serum proteins can be separated into 5 different bands but the same protein using immuno electrophoresis can be separated into 30 different proteins.

The RESOLVING power of immuno diffusion was greatly enhanced bye immuno electrophoresis. This involves the electrophoretic separation of antigen into its constituent proteins followed by immuno diffusion.

This technique is performed on 1% agarose gel. Antigen mixture is FIRST electrophori zed and separated BASED on charge, troughs are then cut in the agarose gel, and antiserum is added to the troughs.

The agarose gel is then incubated 1824hrs during which the antigen and antibody diffuse towards each other. The formation of precipitin bands can be observed for the individual antigen COMPONENTS.

The resolving power of immuno diffusion was greatly enhanced bye immuno electrophoresis. This involves the electrophoretic separation of antigen into its constituent proteins followed by immuno diffusion.

This technique is performed on 1% agarose gel. Antigen mixture is first electrophori zed and separated based on charge, troughs are then cut in the agarose gel, and antiserum is added to the troughs.

The agarose gel is then incubated 1824hrs during which the antigen and antibody diffuse towards each other. The formation of precipitin bands can be observed for the individual antigen components.