Enzyme-linked immunosorbent assay Term Paper Example | Topics and Well Written Essays - 2000 words

Enzyme-linked immunosorbent assay - Term Paper Example Most of the time, this waste is hazardous and may cause detrimental effect to any living organisms, including human (Freedman, 3-9). One of the most common environmental toxicant includes the polychlorinated biphenyls or PCBs. PCBs are man-made organic chemicals belonging to a broad family of hydrocarbons. It was used in many industrial and commercial applications because of its good chemical properties like being non-flammable, high boiling point, chemical stability and good electrical insulating properties. These compounds are widely used for many applicants such as transportation and coolants. PCBs are also used as plasticizers in paints, plastics, and rubber products. It was first manufacture during 1929 but their use had been banned in 1979 upon determining its dangerous effects to both the environment and human health (Davis and Wade, 2-6). PCBs have a range of toxicity and vary in consistency from thin, light-colored liquids to yellow or black waxy solids. These toxic compound s are considered to be persistent organic pollutant for it do not degrade easily and may remain for a long time in the environment. PCBs can contaminate some parts of plants and food crops. PCBs may also be taken up into the bodies of small organisms in that lake including fishes. These toxic compounds may bioaccumulate in these food sources and ingestion may have many adverse health effects in human with symptoms such as skin condition or changes in the blood which may lead to liver damage. Some food which contains PCBs can cause poisoning to the consumers. Moreover, some studies report the health effect of PCBs in children of mothers who were exposed to PCBs (ATSDR, 285-290). Hence, it is important to detect this compound in the environment to prevent its hazardous effect. One of these methods of detection includes the use of Enzyme-Linked Immunosorbent Assay or ELISA Analytical Technique Enzyme-linked immunosorbent assay (ELISA) is a biochemical technique which allows rapid scree ning and quantification of an antigen in a sample. It is used mainly to detect the presence of an antibody or an antigen in a sample. The ELISA has been used as a diagnostic tool in medicine and as detection or measuring tool of environmental toxicants. In ELISA, an antigen is affixed to a surface and a specific antibody is applied over the surface so that it can bind to the antigen. This antibody is linked to an enzyme, and in the final step a substance is added that the enzyme can convert to some detectable signal, which is most commonly a color change in a chemical substrate (Lequin, 2415-2416). Enzyme-linked immunosorbent assay or (ELISA) analysis biochemical technique is used to measurement of organic contaminants such as polychlorinated biphenyls in an environmental sample. Performing an ELISA includes at least one or more antibody with specificity for an antigen. The sample, which has unknown amount of antigen, is immobilized on a solid support either non-specifically or spec ifically. The immobilization process occurs in two ways. One process is by the adsorption to the surface wherein a sample containing an antigen is adsorbed into an inert surface, usually a 96-well polystyrene well. Another process involves capturing another antibody specific to the same antigen, as in a "sandwich" ELISA (Lequin, 2417). The detection antibody is added after the antigen is immobilized, forming a complex with the antibody. This is usually done by washing the surface with a solution of a non-specific protein to block proteins