Immunological and Serological Identification Methods of Viruses

Immunological and Serological identification For most clinical purposes, clear, rapid guidance on the live cause of test are Infection is required rond more rapid bring Saught, Constardly bring methods and gendic methods" and antigen extraction on →Non-Cultural methods, such as antigens or rucleic acid based deteatun. Indirect identification methods:- The se are fregraments of Dat that becognize Complementary Sequences with micro-organisms. binding dis detected by, togging the DNA with a Dadioactive label * cutture and preliminary identification of bacteria in the laboratory is time consuring and relatively labour intensive The technologies fall into three basic groups YPER- 1- →→Target amplification by por, transcription-mediatel amplifiention muckic grid sequente -based amplification →probe amplifiention using ligase chain reaction (or) Q-bets replicase → singal amplification, as in branched DNA assay. →It is possible to detect the presence of an increasing number of species either by per of universal with specific prober →As with Conventional methods, nucleic acids technology has it's limitations, the most frequent b ang Contamination of sample by post complification product → many optiorized per systems claim to be able to detect as fora as two to ten bacteria per millilitre of Spekimen. → Nucleic acid assays for antimicrobial resistens gives are also in use and development the technique uses peptrada nucleic acid with DNA binding capacity. →präst moleculee have a ply amide backbone instead of the sieger phosphate of DNA and RNA, and nucleotide. bases attached to this backbone are able to hybridize by specific base pairing with complementary DNA or Roof Sequences →per complufication of target genes on Conventorally Stained microscope Smears is also possible →All stages of the assay - Sample preporation from agar-grown Colonies, per amplification, hy bridizet -on Conjugation with reported molecule and detector by autorated image Be Cording -cre in a single tadbe within 6-shairs. cassied act A widely used development is that real time per which Combiner Sample amplification with a means for detection of the specific. Product by fluorescence. So that both steps take place conveniently in a reaction tube Single Advantages:- → the per in terms of rapidity, Simplicity. advantages ever ta and camber of →Contamination is effectively eliminated by the tube being closed after amplification. → the DOA product may theorescent dye be detected witha → Quantification of the target DoA is adمع possible with this system, allasing estimation of vived or becterial numbersing specimen. →This techrogus otitzes probes specific for target organisons 'n the sample Loithout the need for specife cutture and allows Quantification of the cell Count. Water agglutination:- → By absorbing specifie antibody to inert partireds arisible cagglutination reaction can be induced in presence of homologous antigen the Latex-based kits are widely used for Serdogird Fraping of organising and detection of toxins and produced by bacteria during growth Enzyme-linked immunosorbent assay →ELISA a specific antibody is attached to the Surface of a plastic well and material containing the test antigen is added →After urishing the presence of the antigen is detected by addition of more of the specific antibody, this time labelled with Enzyme that can initiate a Colour reactor 00 →The ELISA method may also be used in the reverie manner for the quantitative detection of antibodies by absorbing purified andigen to the well before adding test serum. →In immunoglobulin (Ign) santibody capture ELLBA widely used in viraogiral diagnosis. for the detection of IgM →Hacmagglutination and haemadarption certain viruses notably the influenza viruses have the property of attacking to specific receptors on the surface of appropride red blood cells Fluorescence microscopy and immunofluorescence when certain dyes are exposed to oltrevielet light they absorb energy and emit visible light. for example curarnire can be used in this way to stain mycobacterium tuberculosis Antibody molecules can be labelled by Conjugation witha Stuerochrome dye such as theorescein rhodemine when fluorescent antibody is allowed to react with homologos antigen exposed ant a cell surface, this direct immunofluorescence producre affords a highly Sensitive method for the identification of the pertrailer antigen Immuno-polymerase chain reaction →This technique orase out of the fusion oferditaly technology with per methods with him of enhancing capability of antigen defeation systems. →The attached DNA merker can be amplified by Per with appropriate primers and the presence of amplification products shows that mencer DNA attached. to antigen-erotibody Emplex