Precipitation Reactions in Immunology

It is the combination of soluble antigen with soluble antibody, producing visible insoluble complexes.

Affinity refers to the initial force of attraction between a single Fab site on an antibody and a corresponding antigen epitope.

Avidity represents the sum of all attractive forces between an antigen and an antibody, indicating the overall strength of their binding.

<p>The Law of Mass Action states that the binding of antigens and antibodies is reversible and that free reactants are in equilibrium with bound reactants.</p> Signup and view all the answers

<p>It can result in ineffective separation of biomolecules, leading to incorrect analytical results.</p> Signup and view all the answers

<p>The Pro-zone occurs when there is an excess of antibodies, potentially leading to false negative results.</p> Signup and view all the answers

<p>The Post-zone occurs when there is an excess of antigen, which can also cause a false negative reaction.</p> Signup and view all the answers

<p>An incorrect pH can alter the charge of the molecules, affecting their migration rate and overall separation efficiency.</p> Signup and view all the answers

<p>The Zone of Equivalence is the situation where multivalent sites of antigen and antibody are approximately equal, leading to optimal precipitation.</p> Signup and view all the answers

<p>Single diffusion involves a single layer of gel where only one reactant diffuses, while double diffusion involves two reactants diffusing in separate directions within the gel.</p> Signup and view all the answers

<p>The sensitization phase is crucial as it initiates the antigen-antibody binding required for the subsequent lattice formation.</p> Signup and view all the answers

<p>Turbidity is the cloudiness of a solution, measured by the reduction in light intensity caused by scattering and absorption using a detection device.</p> Signup and view all the answers

<p>Lattice formation is influenced by environmental conditions and the relative concentrations of antigen and antibody.</p> Signup and view all the answers

<p>A laser beam in an optical particle counter is used to count particles.</p> Signup and view all the answers

<p>Agglutination increases the size of clumps, making larger clumps uncountable.</p> Signup and view all the answers

<p>The latex particles have a diameter smaller than 1 μm.</p> Signup and view all the answers

<p>Overcentrifugation and contaminated glassware are two causes of false positives.</p> Signup and view all the answers

<p>A delay in testing can lead to false negatives.</p> Signup and view all the answers

<p>Under centrifugation can cause false negatives by not adequately separating agglutinated from non-agglutinated particles.</p> Signup and view all the answers

<p>The Prozone/Post zone phenomenon might occur with excessive antigen.</p> Signup and view all the answers

<p>Inadequate washing can result in false negatives.</p> Signup and view all the answers

<p>Nephelometry measures the amount of light scattered at specific angles as it passes through a suspension, which reflects the concentration of the solution.</p> Signup and view all the answers

<p>Nephelometers measure light scatter at angles ranging from 10 degrees to about 90 degrees.</p> Signup and view all the answers

<p>Rate nephelometry can quantify IgG, IgA, IgM, and IgE, but not IgD.</p> Signup and view all the answers

<p>Passive immunodiffusion is the process where antigen diffuses through a support medium without electrical current to speed up the reaction.</p> Signup and view all the answers

<p>Precipitation occurs as the antigen moves down into the agarose gel, creating a gradient proportional to the amount of antigen present.</p> Signup and view all the answers

<p>In radial immunodiffusion, a well is cut into the gel containing uniformly distributed antibody, and the antigen is applied to this well, allowing diffusion.</p> Signup and view all the answers

<p>The rate of diffusion is affected by particle size, temperature, gel viscosity, and hydration levels.</p> Signup and view all the answers

<p>At the zone of equivalence, antigen-antibody combinations occur in changing proportions, resulting in a stable lattice network in the gel.</p> Signup and view all the answers

<p>Protein A binds the FC portion of IgG antibodies, enhancing the bacterium's ability to evade the immune response.</p> Signup and view all the answers

<p>Agglutination inhibition reactions are based on the competition between particulate and soluble antigens for antibody sites, where lack of agglutination indicates a positive result.</p> Signup and view all the answers

<p>RBCs serve as the indicator particles that show agglutination when viral particles link them together, which can be inhibited by the presence of patient antibodies.</p> Signup and view all the answers

<p>The direct test detects in vivo RBC sensitization, while the indirect test assesses in vitro sensitization and is used for crossmatching and antibody detection.</p> Signup and view all the answers

<p>The Coomb's test is used to investigate hemolytic disease of the newborn, transfusion reactions, autoimmune hemolytic anemia, and drug-induced hemolytic anemia.</p> Signup and view all the answers

<p>Polyclonal antibodies are prepared from various animal sources, such as rabbits and goats, using conventional technology.</p> Signup and view all the answers

<p>The human chorionic gonadotropin (hCG) test is a classic example of agglutination inhibition.</p> Signup and view all the answers

<p>Viruses link RBCs together through their receptors, causing spontaneous agglutination when they are present.</p> Signup and view all the answers