ELISA (ENZYME LINKED IMMUNO SORBITANT ASSAY) and Western blot are both immuno assays.
They rely on use of antigens and antibodies in the reaction.
They are widely used in molecular biology, medical research and also in health care.
ELISA is a quantitative technique which is rapid and relies heavily on production of colors.
While western blot is semi-quantitative technique which relies on production of separated bands of biomolecules. It employs gel electrophoresis to separate the proteins.
Elisa and Western blot
Both these techniques are based on immunology principle but, they have different procedures and applications. So we will see them as similarities and differences.
ELISA vs Western Blot similarities.
Since they follow same principle there are few similarities in between them
Elisa and Western Blot Similarities
|Principle||Based on Immunological assay||Immunological assay|
|Method of assay||Reaction between an antigen and antibody forming a complex||Antigen antibody reactions to form a complex|
|Type of sample||Biological samples||Biological samples only.|
|Compounds than can be analyzed||Proteins, enzymes, hormones, steroids||Enzymes, proteins, hormones.|
But they are many differences between these two techniques. These differences help the researcher decide which of the one of the two to take up.
Elisa vs Western Blot Differences
|Detects||Antibody or antigen in the tissue||Mostly the antigen in the tissue|
|Time for experiment||Very fast like in couple of minutes||Very time taking like 2 to 3 days.|
|Number of samples per experiment||Many sample can be analyzed in a single run like 96 samples per turn using plate readers||Only limited samples like 7 samples per experiment is feasible.|
|Cost of experiment||Comparatively less expensive.||Very expensive as it requires many basic chemical, gels and even blotting paper.|
|Accuracy of detection||The sample detection is very accurate and even the quantity can be clearly known.||Though accurate, quantity can not be clearly known.|
|Technique for operation||It is very easy and even a new experimenter can do with little guidance.||Very complicated and requires practice and standardization of whole procedure.|
|Sensitivity is enhanced by||Washing and removal of unbound proteins.||Here other interfering proteins are removed by gel electrophoresis.|
|Types of experiments||ELISA is of different types like direct, indirect, sandwich type.||It is of different types like southern blot, western and even northern blot.|
|Pictorial demonstration||ELISA is just based on readings by electronic instruments. So it gives only result but no picture||This is based on physical appearance so enables to take photos and depict the result in presentations and publications.|
|Application||Mostly in health care for diagnosis and also in research.||Mostly in research but less preferred in health care due to time span.|
|Age of the technique||It is newer technique||Older technique|
It appears that those who need a pictorial demonstration for publications and presentations for western blot technique. While, those who need just an accurate result like in health care go for ELISA.
In health care ELISA method is used to identify many diseases like AIDS, Hepatitis and other infections by just taking serum sample. It is also widely used in research as it is less time consuming and easy to perform.
On other hand, Western blotting test may be used as a confirmatory test for HIV after ELISA to avoid any false positives.
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