2. WHAT IS ELISA?
Enzyme Linked Immunosorbent Assay (ELISA) is a very sensitive
immunochemical technique which is used to access the presence of
specific protein (antigen or antibody) in the given sample and it’s
quantification.
Antibody: Protein produced by immune systems in response to
pathogen attack.
Antigen: A substance foreign to a living body that stimulates the
production of antibodies. Antigens include proteins, bacteria, and
viruses
3. PRINCIPLE OF ELISA
ELISA is a plate-based assay technique. Along with the enzyme-
labelling of antigens or antibodies, the technique involves following
three principles in combination which make it one of the most
specific and sensitive than other immunoassays to detect the
biological molecule:
An immune reaction i.e. antigen-antibody reaction.
Enzymatic chemical reaction i.e. enzyme catalyses the formation of
colored (chromogenic) product from colorless substrate.
Signal detection and Quantification i.e. detection and measurement of
color intensity of the colored products generated by the enzyme and
added substrate.
9. APPLICATION OF ELISA
This method can be used for testing multiple plants for a single virus
using one well per plant sample.
ELISA is quick and can detect viruses even in the absence of any plant
symptoms of disease.
Also used for seed certification
little amount of antibody for the detection of diseases, and the
process can be semi-automated
It is used for detection of GMO crops.
ELISA is a reliable method and can be used as single tool for the
wheat quality assessment.
10. ELISA TEST IN COTTON
To check the expression level of Trans-gene in cotton.
To study the concentration of BT protein at different growth stages
of cotton plant.
To find out the lethal dose of BT protein for bollworms.
To find out the best cotton genotype expressing stable and
maximum level of BT toxin.
11. PRINCIPLE OF ELISA FOR BT
ANALYSIS
Mostly DAS ELISA is used of BT analysis.
ELISA plates are coated with BT antibodies.
Antigen from cotton sample is added in ELISA plate well.
Conjugate (A secondary antibody) is added in ELISA plate well. It form
a sandwich of Antibody+Antigen+Secondary Antibody.
Substrate (an enzyme) catalyze the antigen and antibody reaction.
Stop solution stop the reaction.
12. APPLICATION OF (ELISA) FOR DETERMINING
DIOXINS IN SEDIMENT AND SOIL SAMPLES
The dioxins comprise a family of compounds chemically referred to as
polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated .
The most toxic of these compounds is 2,3,7,8-tetrachlorodibenzo-p-
dioxin (TCDD), a known human carcinogen.
Immunoassays, such as the enzyme-linked immunosorbent assay
(ELISA), use antibodies to analyze samples rapidly and cost effectively.
ELISA method can be used as a quantitative monitoring tool for
determining dioxin levels in monitoring studies and to determine
dioxin toxic equivalent values in environmental samples.
The feasibility and application of immunosensors to provide field
analytical methods for the dynamic monitoring of toxic substances
13. The methods generally used to measure pesticides are High Performance
Liquid
Chromatography (HPLC) and Gas chromatography/Mass spectrometry
(GC/MS) involving extraction of large volumes of water, extensive
purification and other derivatization and expensive equipment.
(ELISA) appears to be a good alternative, at least for screening purposes.
Good selectivity, sensitivity, precision, and easy measuring many samples in
one run (simultaneous samples analysis), makes immunoassay a cost-
effective method for routine analysis.
ELISA has proved to be a relatively simple, fast analytical
method especially effective when a small volume of water samples has to be
analyzed for
residues.
APPLICATION OF (ELISA) FOR MONITORING ATRAZINE
AND ITS METABOLITES IN THE UN-SATURATED ZONE
