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Definition
| involves reaction of soluble antigen with soluble antibody to produce insoluble complexes (visible) |
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| were developed to detect and measure amounts of antigens & antibodies that are present in very low concentrations |
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| states that free reactants are in equilibrium with bound reactants. It says that the rate of forward reaction equals the rate of backward reaction |
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| How does the law of mass action realte to the test's sensitivity |
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Definition
| It relates to the test’s sensitivity in that the sensitivity of the test is proportional to value of K (the amount of the antigen-antibody complexes) |
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| refers to the precipitation depends on the relative proportion of the antigens & antibodies in the reaction. Maximum binding of antigen & antibody occurs when the aggregate number of antigen and antibody are approximately equal |
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| How does the zone of equivalence relate to the test's sensitivity? |
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Definition
| It relates to the test’s sensitivity in that all testing should take place in this zone in order to be sensitive |
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| relates to the test’s sensitivity in that the antibody needs have a high affinity for the antigen. |
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| related to the test’s sensitivity in that the antibody needs to have a have avidity for the antigen. |
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| is when only one of reactants travels, while the other is incorporated in the gel. The amount of precipitate formed reflects the amount of the assessed antigen |
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| is when both antigen & antibody diffuse from wells and travel toward each other |
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| Rocket Immunoelectrophoresis |
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Definition
| is a single-diffusion electroimmunodiffusion in which antibody is distributed in the gel & antigen is placed in well. The precipitin line (resembling a rocket in shape) reflects amount of tested antigen |
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Definition
| is a single-diffusion technique in which antibody is evenly distributed in the support gel. Antigen is applied to a well cut into the gel & diffuses out from the well forming complexes with antibody. The area of a resulting ring of the lattice is measured and estimated in comparison with standard curve made with titrated amounts of antigen and antibody. |
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| What is the difference between the natural and monoclonal antibodies? |
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Definition
| Natural antibodies are polyclonal, monoclonal antibodies are specific to one epitope |
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Definition
| is a cell resulting from fusion of the Myeloma cell & Plasma cell from an animal immunized with Ag of interest. To purify the population of Hybridoma cells they are cultured in the selective media with aminopterin, which inhibits proliferation of myeloma cells, and subsequently by series of limited dilutions |
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Definition
| are techniques in which all the reactants are mixed together simultaneously and labeled antigen competes with unlabeled patient’s (test) antigen for a limited number of antibody-binding sites. More label detected means that there is less of patient’s antigen |
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| Noncompetitive immunoassays |
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Definition
| are techniques in which the antibody, is called the capture antibody, is first passively absorbed to a solid phase and after that the patient’s antigen is added. After washing, a second antibody with a label is added to the reaction. The amount of label measured is directly proportional to the amount of patient antigen |
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Definition
| immunoassays were developed for the identification of antibodies to nuclear antigen, toxoplasma antigen and many virus antigens. Also detects biological compounds (cortisol, progesterone, serum thyroxine). |
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Definition
| immunoassays based on the change in the fluorescent label on antigen when it binds to antibody. Such change could be related to wavelength emission, rotation freedom or polarity. Homogeneous FIAs (as EIAs) are more commonly used because they are more rapid and easy to perform (do not require separation or washing steps). The amount of measured fluorescence (readout) in homogeneous FIAs is directly proportional to amount of antigen in the tested sample. |
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Term
| sandwich or capture immunoassays |
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Definition
| antibodies are bound to the solid phase. The test sample with antigen is added to the solid phase with attached antibody (Antigen capture step). An antigen to be detected in this test must have multiple epitopes. After incubation and wash steps an enzyme-labeled antibody against antigen is added. This second antibody must be specific for epitopes different from those recognized by the solid phase antibody. Enzymatic activity in the capture assays is directly proportional to the amount of antigen in the test sample |
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| Direct immunofluorescense |
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Definition
| is when antibody which is conjugated with a fluorescent tag is added directly to unknown antigen that is fixed to a microscope slide. After incubation and wash steps, the slide is read using a fluorescence microscope |
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Term
| indirect immunofluorescense |
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Definition
| is when (1) Incubation of the test serum with a known antigen is attached to a solid phase. (2) After washing, an immunoglobulin labeled with a fluorescent tag is added. This method allows use of one type of labeled antibody with no need to label each antigen-specific reagent antibody. |
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Definition
| • An mAb must be produced for diagnostic purpose using cell-specific markers as antigens that are very specific |
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| Fout basic tests for HLA typing |
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Definition
• Complement dependent cytotoxicity
• Molecular-based methods
• ELISA
• Flow Cytometry |
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Term
| Which part of the radial immunodiffusion (RID) test system contains antibody? |
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Definition
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| A patient s sample contains very large amount of antibody, but the readout of the precipitation reaction test is negative. What could be the reason of such result? |
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Definition
| Prozone Phenomenom and a shift from the zone of equivalence |
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| An IFE performed on a serum sample showed a narrow dark band in the lanes containing anti- gamma and anti-lambda antibodies. How this result should be interpreted? |
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Definition
| Monoclonal IgG gammopathy |
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| What comprises the indicator system in an ELISA for detecting Ab? |
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Definition
| Enzyme-conjugated Ab + enzyme-specific chromogenic substrate |
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| Heterogeneous EIA is a method of choice compared to homogeneous EIA for detecting certain analytes present in low concentrations for all the following reasons, except: |
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Definition
| There is no disadvantage of the nonspecific protein binding in these assays |
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| The absorbance of a sample measured by ELISA is greater than the highest standard value. What action should be taken? |
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Definition
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| Which statement best describes Immunophenotyping? |
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Definition
| A methodology allowing cells identification based on the repertoire of their specific markers using labeled Abs |
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| C3b and Fc receptors are expressed on |
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Definition
| B lymphocytes and monocytes |
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| Which of the following terms describes a graft between individuals, which are not genetically identical but are belonging to the same species? |
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Definition
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| Bone marrow is usually depleted from CD8+ T cells prior to the bone marrow transplantation procedure. Why? |
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Definition
| To preclude/minimize development of the graft versus host disease |
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| In the precipitation reaction the sensitivity of the test is proportional to value of K |
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Definition
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Term
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Definition
| Excess of Abs in the test tube during the precipitation reaction |
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| The true statement/s about the electrophoretic techniques is/are: |
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Definition
| Electric current is forced through the gel, causing Ag & Ab to migrate and They speed up and sharpen the results of the immunodiffusion technique |
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| Immunophenotyping is a technology allowing |
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Definition
Live cell sorting of the purified cell populations, Diagnosis of cancers and
Identification of the cells functional activity at the specific time point |
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Term
| Hybridoma cells are immortal . They can be frozen in the liquid nitrogen, and when needed could be thawed and placed in the culture media where they can indefinitely produce the Abs of interest |
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Definition
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Term
| In the competitive heterogeneous enzyme immunoassays |
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Definition
| Washing to remove any nonspecifically bound Ag is a required step and Enzyme activity is inversely proportional to the concentration of the test substance |
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Term
| ELISA is commonly used because this test |
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Definition
| Allows detection of auto-Abs & Abs in viral infections and Has high sensitivity |
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