Antigen Antibody Reaction Flashcards
Antigen antibody reaction
Reaction between antigen and antibody and there is no irreversible alteration in either antibody or in antigen
General properties of antigen antibody reaction
Specific
Noncovalent bond
Strength -affinity and avidity
Why antigen and antibody reaction is specific
Antigen antibody reaction - specific interaction between epitope of an antigen with corresponding paratopw of homologous antibody
Non covalent reaction of ag-ab reaction
Hydrogen bond
Electrostatic interactions
Hydrophobic interactions
Van der waals forces
Affinity
It is the sum total of noncovalent interactions between a single epitope of an ag with its corresponding paratope of an antibody
Avidity
The affinity of all the binding sites when multivalent antibody react with a complex antigen carrying multiple epitopes
What is immunoassay
The diagnostic test based on the ag- ab reaction are called as immunoassay
Types of immunoassay
Antigen detection assays:detect the ag in the patient sample by employing specific ab
Antibody detection assays:detect ab in patients sample by employing specific ag
Difference between the qualitative and quantitative test
Qualitative: quantitative:
Undiluted specimen. Diluted. 2. specimen
Positive or negative results
Exact count of . 3. the antibody
Semi quantitative and quantitative assay
Semiquntitative: so much of dilution
Ex: widal test and VDRLtest
Quantitative: exact count
Ex: ELISA AND CLIA
Types of ag-ab reaction
Conventional techniques
Newer techniques
Conventional techniques
Precipitation reaction
Agglutination reaction
Complement fixation reaction
Neutralization test
Newer techniques
Enzyme linked immunoassay
Enzyme linked fluorescent assay
Immunofluorescence assay
Chemiluminescence linked immunoassay (CLIZ)
Immunohistochemistry
Rapid test
Lateral flow assay
Flow through assay
Waster blot
