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Polyclonal antibody
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Which of the following is NOT true about antibodies a. an antibody has more than one antigen binding site b. a pathogen can have different epitopes c. a pathogen makes more than one antigen?
C is false.A pathogen can have multiple epitopes and antigens. A single antigen is simply one molecule, and the cell surface is littered with millions of antigens.
How monoclonal antibody are produced?
by the help of hybridoma technology. single type of B cell which is sensitized with single epitope of antigen fysed with a myeloma cell. then that fused cell produce single type of antibody....that is monoclonal antibody.....
Why polyclonal antibody solution is able to precipitate its antigen protein whereas monlclonal antibody solution has hard time to do so?
Polyclonal antibody recognizes several epitopes on the target protein while monoclonal antibody recognizes only single epitope. Sometimes, monoclonal antibodies are not able to precipitate the antigen because the epitope might need to be exposed on the surface of the antigen to be recognized by the antibody. Since the epitope might be hidden and it's a single epitope that is recognized by the monoclonal antibody, the propability of the antibody to reconize the epitope is lower compared with the polyclonal antibody that recognizes several epitopes on the target protein.
What bind with specific antigens in the antigen-antibody response?
The Fab portion of the antibody is what determines the idiotype. The Fab portion consists of both a heavy and light chain and is connected to the Fc region (isotype). Every B cell will express a different Fab structure and in a single B cell it will produce only the same Fab.
Why polyclonal antibody tend to have cross-reaction compare to monoclonal antibody?
Polyclonal antibody recognizes several epitopes on the target protein while monoclonal antibody recognizes only single epitope, hence monoclonal antibodies are more specific than polyclonal antibodies. However, sometimes MAbs are not able to precipitate the antigen because the epitope might need to be exposed on the surface of the antigen to be recognized by the antibody. Since some of the epitope might be hidden and it's a single epitope that is recognized by the monoclonal antibody, the propability of the antibody to reconize the epitope is lower compared with the polyclonal antibody that recognizes several epitopes on the target protein this is the reason for the tendency of polyclonal antibodies to have cross-reaction as compared to MAbs. by Victor S Gruezo Jr
What does the Clonal Selection Theory state?
The Clonal Selection Theory explain how the immune system can be both diverse and very specific at the same time.The theory states:All antibodies are precommitted to making a single antibody with a single specificityA single cell produces only one antibody which interacts with only one antigen with the highest specificityWhen the right antigen interacts with that cell, it leads to clonal expansion and proliferation of that cell, so that many daughter-cells are made with the exact same specificityThe ability to recognise an antigen is dependent on a receptor, and the receptor is a product of the same cell that secretes the antibody. This ensures that made antibodies will fit with the antigen they are supposed to bind.A clone is defined as a group of cells in which all daughter cells are equal in their specificity
Can monoclonal antibodies be specific for multiple antigenic determinants?
No, they are pure antibody preparations specific for a single antigenic determinant.
What is Radial immunodiffusion test?
Radial immunodifusion tests for the presence/absence of viral antigens in a sample. Antigen diffuses into the agar which contains specific antibody and a ring of precipitate is formed when antigen-antibody interactions occur. The diameter of the ring is directly proportional to the concentration of the antigen and can thereby be used to quantitate the amount of antigen. A reverse radial immunodiffusion test, in which antigen is incorporated in the agar, can be used to quantitate the amount of antibody in a sample.Capable of detecting and quantifying antigens, the radial immunodiffusion is a technique in which antibody is incorporated into an agar gel, followed by the addition of antigen into formed wells of the antibody-containing agar. After incubation, diffusion proceeds and the antigen which has been allowed to diffuse into the agar reacts with specific antibody, produces a ring of precipitation that will form at the point where the antigen and antibody have reached equivalence. However, as diffusion proceeds radially from the well, an excess of antigen develops in the area of the precipitate causing it to dissolve only to form once again a greater distance from the site of origin. Precipitate will occur only at the zone of equivalence. The greater the concentration of the antigen in the well, the faster precipitation will take place. Diffusion of antigen will proceed from the well with a build-up of precipitate at the outer edge of the ring, where the antigen will be encountering additional antibody. The system is initially in a dynamic state, as the rings increase with time. A static state of precipitation is reached when all the antigen has diffused into the gel and precipitation is complete.The precipitation ring surrounds an area proportional to the concentration of antigen measured 48 to 72 hours following diffusion, with antibody concentration kept constant. The diameter of the precipitin ring can be used to quantify the antigen concentration through comparison with antigen standards. Standard curves can be employed using these known antigen standards. The antigen concentration is easily determined through measuring the diameter of the precipitation ring. This technique provides sensitivity in detecting an antigen to 1 to 3 micrograms/mL antigen. For greater sensitivity, ELISA assays should however be used. (2,3)Standard Calibration CurveIn a simple experiment, numerous known BSA concentrations and a single known sample, can be placed into individual wells within an anti-BSA agar plate. The diameters of the precipitin discs can then be measured and plotted on semi-logarithm graph paper. The standard calibration curve can then be plotted as the BSA concentration versus the diameter of the precipitin discs. The curve allows for the determination of the unknown sample concentration. The standards from each formed a gradient of precipitin ring in direct relation to their antigen concentration. Slight procedural differences, such as poor well filling and disc measurements, can lead to slight deviations of a few standard points
What is an antibody and what do?
Antibodies (also known as immunoglobulins,abbreviated Ig) are gamma globulin proteins that are found in blood or other bodily fluids of vertebrates, and are used by the immune system to identify and neutralize foreign objects, such as bacteria and viruses. They are typically made of basic structural units-each with two large heavy chains and two small light chains-to form, for example, monomers with one unit, dimers with two units or pentamers with five units. Antibodies are produced by a kind of white blood cell called a plasma cell. There are several different types of antibody heavy chains, and several different kinds of antibodies, which are grouped into different isotypes based on which heavy chain they possess. Five different antibody isotypes are known in mammals, which perform different roles, and help direct the appropriate immune response for each different type of foreign object they encounter.Though the general structure of all antibodies is very similar, a small region at the tip of the protein is extremely variable, allowing millions of antibodies with slightly different tip structures, or antigen binding sites, to exist. This region is known as the hypervariable region. Each of these variants can bind to a different target, known as an antigen. This huge diversity of antibodies allows the immune system to recognize an equally wide diversity of antigens. The unique part of the antigen recognized by an antibody is called an epitope. These epitopes bind with their antibody in a highly specific interaction, called induced fit, that allows antibodies to identify and bind only their unique antigen in the midst of the millions of different molecules that make up an organism. Recognition of an antigen by an antibody tags it for attack by other parts of the immune system. Antibodies can also neutralize targets directly by, for example, binding to a part of a pathogen that it needs to cause an infection.The large and diverse population of antibodies is generated by random combinations of a set of gene segments that encode different antigen binding sites (or paratopes), followed by random mutations in this area of the antibody gene, which create further diversity. Antibody genes also re-organize in a process called class switching that changes the base of the heavy chain to another, creating a different isotype of the antibody that retains the antigen specific variable region. This allows a single antibody to be used by several different parts of the immune system. Production of antibodies is the main function of the humoral immune system.
What is an antibodie?
Antibodies (also known as immunoglobulins,abbreviated Ig) are gamma globulin proteins that are found in blood or other bodily fluids of vertebrates, and are used by the immune system to identify and neutralize foreign objects, such as bacteria and viruses. They are typically made of basic structural units-each with two large heavy chains and two small light chains-to form, for example, monomers with one unit, dimers with two units or pentamers with five units. Antibodies are produced by a kind of white blood cell called a plasma cell. There are several different types of antibody heavy chains, and several different kinds of antibodies, which are grouped into different isotypes based on which heavy chain they possess. Five different antibody isotypes are known in mammals, which perform different roles, and help direct the appropriate immune response for each different type of foreign object they encounter.Though the general structure of all antibodies is very similar, a small region at the tip of the protein is extremely variable, allowing millions of antibodies with slightly different tip structures, or antigen binding sites, to exist. This region is known as the hypervariable region. Each of these variants can bind to a different target, known as an antigen. This huge diversity of antibodies allows the immune system to recognize an equally wide diversity of antigens. The unique part of the antigen recognized by an antibody is called an epitope. These epitopes bind with their antibody in a highly specific interaction, called induced fit, that allows antibodies to identify and bind only their unique antigen in the midst of the millions of different molecules that make up an organism. Recognition of an antigen by an antibody tags it for attack by other parts of the immune system. Antibodies can also neutralize targets directly by, for example, binding to a part of a pathogen that it needs to cause an infection.The large and diverse population of antibodies is generated by random combinations of a set of gene segments that encode different antigen binding sites (or paratopes), followed by random mutations in this area of the antibody gene, which create further diversity. Antibody genes also re-organize in a process called class switching that changes the base of the heavy chain to another, creating a different isotype of the antibody that retains the antigen specific variable region. This allows a single antibody to be used by several different parts of the immune system. Production of antibodies is the main function of the humoral immune system.
What are blood antibodies?
Antibodies are cells that are made in the body. They are involved in immunity. Any foreign invader (antigen) that enters the body will be engulfed by its corresponding antibody, if that antibody is present in the body.
What does antibodies mean?
Antibodies (also known as immunoglobulins,abbreviated Ig) are gamma globulin proteins that are found in blood or other bodily fluids of vertebrates, and are used by the immune system to identify and neutralize foreign objects, such as bacteria and viruses. They are typically made of basic structural units-each with two large heavy chains and two small light chains-to form, for example, monomers with one unit, dimers with two units or pentamers with five units. Antibodies are produced by a kind of white blood cell called a plasma cell. There are several different types of antibody heavy chains, and several different kinds of antibodies, which are grouped into different isotypes based on which heavy chain they possess. Five different antibody isotypes are known in mammals, which perform different roles, and help direct the appropriate immune response for each different type of foreign object they encounter.Though the general structure of all antibodies is very similar, a small region at the tip of the protein is extremely variable, allowing millions of antibodies with slightly different tip structures, or antigen binding sites, to exist. This region is known as the hypervariable region. Each of these variants can bind to a different target, known as an antigen. This huge diversity of antibodies allows the immune system to recognize an equally wide diversity of antigens. The unique part of the antigen recognized by an antibody is called an epitope. These epitopes bind with their antibody in a highly specific interaction, called induced fit, that allows antibodies to identify and bind only their unique antigen in the midst of the millions of different molecules that make up an organism. Recognition of an antigen by an antibody tags it for attack by other parts of the immune system. Antibodies can also neutralize targets directly by, for example, binding to a part of a pathogen that it needs to cause an infection.The large and diverse population of antibodies is generated by random combinations of a set of gene segments that encode different antigen binding sites (or paratopes), followed by random mutations in this area of the antibody gene, which create further diversity. Antibody genes also re-organize in a process called class switching that changes the base of the heavy chain to another, creating a different isotype of the antibody that retains the antigen specific variable region. This allows a single antibody to be used by several different parts of the immune system. Production of antibodies is the main function of the humoral immune system.
