Direct Line

Immunoassays

Immunoassays combine the principles of chemistry and immunology enabling scientific tests, e.g. enzyme immunoassays and immunoblotting for a specific and sensitive detection of the analytes of interest. The basic principle of these assays is the specificity of the antibody-antigen reaction. Though being very specific and sensitive, immunoassays are easy to perform, which has contributed to its  widespread use and tremendous success. In immunoblotting like the Western Blot of electrophoretically separated proteins a single one can be identified by its antibody.

RIAs (Radioimmunoassay) and enzyme immunoassays like ELISA (Enzyme-linked immunosorbent assay), LIA (luminescent immunoassay),  and FIA (fluorescent immunoassay) are widely used in research, drug discovery and diagnostics for highly specific and cost efficient detection of analytes not detectable with other techniques. The antibodies – either used as primary or secondary ones – are labelled with radioisotopes (e.g. 125I), fluorescent dyes (e.g. FITC) or enzymes (e.g. HRP or AP) which catalyse fluorogenic or luminogenic reactions. As immunoassays usually involve multiple washing, dispensing and incubation steps, assay workstations are often used to automate the process.

Applications for Immunoassays:

  • Tumour Markers, e.g. AFP, CEA, hCG, PSA…

  • Cardiac Markers, e.g. CK-MB, CRP, Digoxin, Myoglobin…

  • Cell based Assays, e.g. cell cytotoxicity…

  • Allergy, e.g. histamines, egg, milk, allmonds…

  • Growth Deficiency, e.g. hGH

  • Enzyme acivity

  • Hormone and Steroid Screening, e.g. T4, fT3, TSH…

  • Drug Abuse Screening, e.g. amphetamines, cocaine, LSD…

  • Immunological Screening

  • Infectious Diseases, e.g. Chlamydia, CMV, Hepatitis, Rubella…

  • Veterinary, e.g. bacterial infection, fertility, drugs, BSE…

  • Food and Beverages, e.g. pathogens, toxins…

  • Water Analysis, e.g. bacterial contamination, toxins, heavy metals…

  • Agriculture, e.g. endotoxins, pesticides…

  • Environment, e.g. industrial chemicals, pesticides, surfactants…

     

     

Suitable Instruments for Immunoassay