ELISA Test : All types with Mechanism discussed in details : Microbiology
ELISA - Enzyme Linked Immunosorbent Assay
Different Types of Elisa and their principles.All types of ELISA test.
The enzyme-linked immunosorbent assay (ELISA) (/ɪˈlaɪzə/, /ˌiːˈlaɪzə/) is a commonly used analytical biochemistry assay, first described by Engvall and Perlmann in 1971.[1] The assay uses a solid-phase enzyme immunoassay (EIA) to detect the presence of a ligand (commonly a protein) in a liquid sample using antibodies directed against the protein to be measured. ELISA has been used as a diagnostic tool in medicine, plant pathology, and biotechnology, as well as a quality control check in various industries.
In the most simple form of an ELISA, antigens from the sample are attached to a surface. Then, a matching antibody is applied over the surface so it can bind to the antigen. This antibody is linked to an enzyme, and in the final step, a substance containing the enzyme's substrate is added. The subsequent reaction produces a detectable signal, most commonly a color change.
Performing an ELISA involves at least one antibody with specificity for a particular antigen. The sample with an unknown amount of antigen is immobilized on a solid support (usually a polystyrene microtiter plate) either non-specifically (via adsorption to the surface) or specifically (via capture by another antibody specific to the same antigen, in a "sandwich" ELISA). After the antigen is immobilized, the detection antibody is added, forming a complex with the antigen. The detection antibody can be covalently linked to an enzyme or can itself be detected by a secondary antibody that is linked to an enzyme through bioconjugation. Between each step, the plate is typically washed with a mild detergent solution to remove any proteins or antibodies that are non-specifically bound. After the final wash step, the plate is developed by adding an enzymatic substrate to produce a visible signal, which indicates the quantity of antigen in the sample.
Of note, ELISA can perform other forms of ligand binding assays instead of strictly "immuno" assays, though the name carried the original "immuno" because of the common use and history of development of this method. The technique essentially requires any ligating reagent that can be immobilized on the solid phase along with a detection reagent that will bind specifically and use an enzyme to generate a signal that can be properly quantified. In between the washes, only the ligand and its specific binding counterparts remain specifically bound or "immunosorbed" by antigen-antibody interactions to the solid phase, while the nonspecific or unbound components are washed away. Unlike other spectrophotometric wet lab assay formats where the same reaction well (e.g., a cuvette) can be reused after washing, the ELISA plates have the reaction products immunosorbed on the solid phase, which is part of the plate, and so are not easily reusable.
Contents
1 Principle
2 History
3 Types
3.1 Direct ELISA[18]
3.2 Sandwich ELISA
3.3 Competitive ELISA
3.4 Reverse ELISA
4 Commonly used enzymatic markers
5 Applications
6 See also
7 Notes and references
8 External links
Пікірлер: 101
I thought of skipping this topic but now I understood this so well with crystal clarity✨ because of your teaching.🥰🥰 Thank you so much sir❤️
Video is informative but wanted to bring to your notice that , In competitive ELISA - no Color means positive(I.e no antigen is free to bind the enzyme coated antibody) so the added enz. Coated antibody are washed and on addition of the substrate no Color produced . If Color is produced it means antibody are not present in the pt. Sera I.e on added enz. Coated antibody are bound to antigen on plate and on addition of the substrate Color produced.
I really appreciate you for creating such a great content ❤️ keep uploading 🔥
Thanks. It is really helpful. Have zero knowledge about it but after watching this video. I can explain it in my own words ❤
Thank you!!!! this was such a great intro explanation
First of all thanks for uploading video....simple n clear cut explaination
Easy and simple... Very good explanation thnk u
Excellent explained ....👍 Thank you
you saved me THANK YOU great explanation
Very helpful and the explanation is clear, thank you so mucj
thank you so much, Dr !
Thank you for making it simple
Very informative video...Thank you very much 🙏
very well explained thank you so much
thanks, bro really helpful nice explanation...
Awsome video... Thanku soo much sir🙂
more helpful easily understand tq so much 🥰
Thank you for clear my doubts
Really really thanks for this
Ultimate vedio , very good explaination 👌👌👌.. Really ur explanation was sooo good👍
Very helpful video ☺️
Thank u for sharing this video..😊😘👍👍👍
Very easy for learning thank you
This is helpful. Thank you
Thank you so much sir , Your way of teaching is very good ... I have subscribed your channel right now
Thanks for this ❤
I Really appreciate you thanks a lot
Very helpful vedio Thnx sir
Fully explained thanku sir
Directly jumped into topic
very helpful , thank you
Very nice explanation 👌
Today is my exam thank u so much u made my day 🙏
thank u so much
Thanku sir it's really helpful to me
Thank you sir
Thank you.
Helpful video 👍
Thank you sir ❤️
Nice explanation, thanks for the lecture
Thank you
Helpful content
Thanks
Nice explanation
Thank u so much Sir
Very very helpful tnq
Thank u so। Much 💙
Very use full vedio
Nice explanation 🤗🤗👏tqq:)
Thanks sir
Thankyou !
Thank you for making it simple ❤️
Am rushing towards my exams but this video is super ❤❤❤ thank you Sir for the video
Thanks man
Exelent thanks
You explained it really well.. thank you 😊
Please recheck your explanation of competitive elisa. As the second antibody is of the same type of the first one, so it will not react and no color will be produced. No color = positive result
@POChinkiGaming
2 жыл бұрын
Agreed, if Color produce in Competitive ELISA it means the results is negative while on the other hand No color production gives Positive Results
Very helpfull
Amazing
Nice very good helpful
Tnku Tnku so much sir...es topic ko easy bnane ke liye nhi to mujhe ye topic pta nhi kya lg rha tha 😤😤😤😤
Bro you can add notes also along with this so that it will be more useful 🙏
Thank u sir
wah maza hi agya
Competitive and indirect Elisa looks the same ?
Thnx👍🏻
Awesome
Helpful
Very nyc
Supeb sir
I like it bro
Why Sandwich ELISA is more sensitive?
@afreenlirani
3 жыл бұрын
A sandwich ELISA is more sensitive and robust as the antibody binds to two sites on the antigen. This increases the binding specificity of the primary capture antibody to the antigen as well as the binding specificity of the detection antibody to the antigen.
@soumighosh9075
3 жыл бұрын
Thank you Sir
How can i listen this video in urdu?
In competitive appearance of colour indicates -ive test
no colour formation in competitive elisa (reference cp baveja)
❤
❤👍🏻
What are the reasons to opt for a specific type of ELISA test? The direct ELISA and competitive ELISA seemed very similar, so when do you use which one?
@chrisallen5025
3 жыл бұрын
i realize it's pretty randomly asking but does anyone know of a good website to watch newly released movies online?
@jakobfinn4339
3 жыл бұрын
@Chris Allen I would suggest flixzone. Just google for it :)
@aydenjackson8328
3 жыл бұрын
@Jakob Finn yup, been watching on flixzone for since march myself :D
@chrisallen5025
3 жыл бұрын
@Jakob Finn Thanks, I signed up and it seems like they got a lot of movies there :) I really appreciate it !!
@jakobfinn4339
3 жыл бұрын
@Chris Allen glad I could help xD
Osmmm
Why we use secondary antibody ??
@afreenlirani
3 жыл бұрын
Secondary antibodies provide signal detection and amplification along with extending the utility of an antibody through conjugation to proteins. ... Secondary antibodies help increase sensitivity and signal amplification due to multiple secondary antibodies binding to a primary antibody. I hope this helps
Where is reverse ELISA?
Competitive elisa 8:24
👍
You are not mentioned in any substrate name similarly not washing agents..🥺
@user-qi5jw8xf9k
2 ай бұрын
Substrates are 1) Alkaline phosphate - Paranitrophenyl phosphate (blue clr) 2) Horseradish peroxidase - tetramethyl benzedene (yellow clr) The buffer solution is used to wash
Broo...first explain why we do it
Why don't you tell the concept🤦🤦👎👎
Sbko english ka 14 banna h🤦♀️🤦♀️ Bhai atlst hindi m agar sahi se explain kr skte ho to please explain it.. Hindi and english doesn't matter if you have good communication skills.. English just a language please don't do. That
bad language
Thank you sir
Thanks