Precipitation Serological Tests PDF

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n ma ga Precipitation Serological Tests LJ La n One of the easiest of serological tests Soluble Ag & Ab interact and form a lattice that develops into a visible precipitate. Precipitation reaction Occur best when antigen and antibody are present in optimal proportions (Equivelance). Antibodies that aggregate soluble antigens are called LJLangaman precipitins. Medical Laboratory Science n ma n ga n La ma Precipitation Curve LJ LJ La n ga Precipitation in Liquid Prozone Zone of equivalence Postzone Precipitation in gel Two types of immunodiffusion reactions can be used to determine relative concentrations of antibodies or antigens 1. Radial immunodiffusion (the Mancini method) Equivalence – Ab excess Ag excess 2. Double immunodiffusion(the Ouchterlony method) Lattice formation  n n ma ma n ga n ga LJ La Ouchterlony method LJ La Radial immunodiffusion In radial immunodiffusion, an antigen sample is placed in a well and allowed to diffuse into agar containing a suitable dilution of an antiserum. As the antigen diffuses into the agar, the region of equivalence is established and a ring of precipitation, a precipitin ring, forms around the well The area of the precipitin ring is proportional to the concentration of antigen. n n ma ma n ga n ga La La LJ LJ Measurement of precipitation by light scattering Immunologic Assays Performed by Nephelometry 1- Turbidometry 2- Nephlometry C8 Nephelometry Acid α1-glycoprotein Ceruloplasmin Turbidimetry precipitation in solution Albumin α1-Antitrypsin Complement components α2-Macroglobulin (C1r, C1s, C2, C3, C4, C5, C6, precipitation in solution measurement of scattered C7, C8) C1 esterase inhibitor (C1 light (proportional to number inhibitor) C-reactive protein (CRP) measurement of light extraction of insoluble complexes C3 Cryofibrinogen (precipitate absorption) C3b inhibitor (C3b inactivator) Cryoglobulins standard curve C3PA (C3 proactivator, properdin Haptoglobin standard curve factor B) Hemopexin C4 C6 Immunoglobulins C7 Properdin factor B Transferrin  n n ma ma n ga n ga J La La LJ Advantages Of Turbidimetry And NephelometryL Electro-Immnodiffusion Measurement of serum proteins‘ concentration (immunoglobulins, acute-phase proteins, complement 1. Immunoelectrophoresis (IEP) 2. Rocket Electroimmunodiffusion (EID) components C3, C4, transferrin, albumin,…) 3. Counterimmunoelectrophoresis (CIEP) Rapid 4. Immunofixation Fully-automated techniques For large quantity of samples