Competitive ELISA Tutorial 1: How a Competitive ELISA Works

Here, we discuss the concept behind a Competitive ELISA (Enzyme-Linked Immunosorbent Assay). Competitive ELISAs are commonly used to measure the amount of a specific protein, antibody, or metabolite in a given sample. Though Competitive ELISAs may initially be hard to understand, we hope that this brief video will make some essential concepts as easy to understand as possible.
Our ELISA tutorials are kindly sponsored by Calbiotech. Click here to see Calbiotech's ELISA kits: protocol-place.com/Calbiotech
This video is a part of our ELISA Tutorial Series. Here are all of the videos in this series:
ELISA Tutorial 1: Understand How an ELISA Works - • ELISA Tutorial 1: How ...
ELISA Tutorial 2: Coating and Blocking the ELISA Plate - • ELISA Tutorial 2: Coat...
ELISA Tutorial 3: Preparing and Adding Samples to the ELISA Plate - • ELISA Tutorial 3: Prep...
ELISA Tutorial 4: Finishing the Assay (Sandwich ELISA) - • ELISA Tutorial 4: Fini...
ELISA Tutorial 5: Preparing ELISA Data in Excel for Analysis with GraphPad Prism - • ELISA Tutorial 5: Prep...
ELISA Tutorial 6: How to Analyze ELISA Data with GraphPad Prism - • ELISA Tutorial 6: How ...
Competitive ELISA Tutorial 1: How a Competitive ELISA Works - • Competitive ELISA Tuto...
Competitive ELISA Tutorial 2: How to Use Calbiotech's Competitive ELISA Kits - • Competitive ELISA Tuto...
Competitive ELISA Tutorial 3: Analyzing Typical ELISA Data in Excel - • Competitive ELISA Tuto...
We hope you enjoy watching and benefit from our tutorials. If so, please take a minute to "like," or better yet, share them with others!
Thanks for watching!
Youssef Farhat
Protocol Place: protocol-place.com
**Check out some of our other tutorials via the links below**
Competitive ELISA Tutorials - - - • Competitive ELISA Tuto...
ELISA Tutorials - - - • ELISA Tutorial 1: How ...
Gelatin Zymography Tutorials - - - • Gelatin Zymography Tut...

[@sir9integra9jr]

explanation starts at 2:14 if you already have a grasp on what antibodies, enzymes, and conjugation are

[@michaelhammonds7359]

Dr. Hammonds: Thanks, you took a complex idea and made it much more simple and easier to understand.

[@mbalenhledlamini2632]

10 years later and this is still the best explanation I have found. Thank You!

[@maddieharman8377]

THANK YOU!!! Thanks so much for making this video! My classmates and I were so confused about competitive ELISAs and this video really helped clear things up for us! We really appreciate your help!

[@Daniel47yes]

BEST EXPLANATION EVER! Te pasaste flaco, grande!

[@alexgalvezmorante9611]

This video has helped me a lot. Thank you for your work.

[@DaLokNessMonster]

very clearly explained! the illustrations really help to get the information across!

[@basetwahiz1136]

Very helpful, i have been searching the chemistry behind it, you made it really easy thank you

[@leabilicic6384]

Simply the best video about competitive ELISA I have ever found on the internet :D

[@nielp91]

Better than the video my super gave me when I started working. This is on point!

[@janejordan85]

Very helpful! :) Thank you from Italy!!

[@Hamlet137475]

pretty straightforward, good presentation, i liked it!

[@angryblackwomanphd4241]

YOU JUST HELPED ME UNDERSTAND MY RAW DATA! THANKS!

[@skyisnotblueskyisblue2302]

thank you so much for this!!!!! i was really confused about how competitive elisa works

[@yourfuturedocburenbeiya]

This is awesome!! Thank you so much for this video explanation!!

[@sarahe.s7231]

Big thanks.. Praying for you of success forever 🙏💙

[@julitequenum1128]

This is great. Simple explanation. Thank you so much!

[@ScheveSneeuwSchuifSchep]

Thank you so so so much, this is really saving me for my exam for bioanalytical techniques tmorrow

[@yelenasofiapajaroesquivia3634]

THANKS!! Excellent explanation!! it helped me a lot!

[@Daniel-cj1pt]

thx my friend very good informative and clear video!!

[@jonathanmartinbenitez7427]

THE BEST EXPLANATION BY FAR

[@shoootingstarss]

this is so clear. thank you

[@kateillac]

this was a great, easy to follow presentation. thank you so much.

[@kateillac]

Just Observing what an original comment, you must find yourself to be so funny. Gender jokes are outdated dude, move on.

[@bobby-joe8063]

Katie Ritchie you on tinder?

[@alaaal-maliki6232]

Love all your work and your tutorial!!! Keep it up ;)

[@brijeshverma4677]

Thank you so much. This was really helpful

[@NGOCNGUYEN-df8jk]

this video saves my life thanks a lot

[@nwilczyn]

the best competitive elisa vid I have seen... still, it is hard to keep this variation on the elisa process straight in my head (grrrr)... any tips or mental tricks?

[@Rachel-lz8fe]

Thank you so much. I could understand clearly!

[@bakeezawzaghlool]

Thanks a lot helped me with the topic , I have an exam tomorrow :)

[@Antoine_Fainthearted]

Sir, this helped me a great deal, my thanks!

[@abdul4boys]

Thanks a million, the video was very helpful

[@nazminizarimi2030]

thanks for this video. helped me a lot too

[@sam_liston98]

perfect explanation man, keep going👌

[@mustafatalib2367]

It is quite informative thank you for this effort

[@godfreykamugisha4033]

Thanks for your good clarification

[@daviejeon]

Thanks for the video. It was easy to understand.

[@KanyesigyeGeofrey]

???

[@akasprime]

very clear !! ...excellent video

[@GK090]

So helpful! Thank you so much!

[@siawweilai2414]

Thank you sir for the clear explanation

[@rajyalaxmikonathan832]

It was very helpful,thanks a lot

[@retomatinho]

THANK YOU. I really needed this explanation, I was very confused lol

[@056vatsalapandey3]

thank you so much (tears in my eyes)

[@QFBPLR]

Está genial tu explicación, gracias (Y)

[@sakshipant9441]

Easy to understand thank u..

[@AZ-qx1xd]

Thank you! so clear..

[@charityubani1888]

Clearly understood

[@1627anat]

Thanks!

[@fukyouisrael]

thanks you for the informations

[@spicyotato7940]

Very helpful, thanks :)

[@mostaphaaaa3]

so useful thanks a lot

[@rayans1832]

Thank you very much

[@entedaralsaadi21]

thank you so much

[@nathanielhogge9548]

saved my life

[@tarteelmohammed3257]

Thank you

[@zinaadams2389]

u r amazing, thanks so much!

[@talashpeygir2621]

thank you

[@sandri8683]

Wonderfull!!

[@nasira.4232]

thanks

[@sajs7778]

شكرا جزيلا

[@fatdah8140]

Merci beaucoup

[@nwilczyn]

my question is, if I run out of milk for my breakfast cereal, could I substitute BSA?

[@severerevenge8575]

Greatest

[@Khaledf]

Thank you. BUT Why is it used competitively? Wouldn't be more easier to use direct or indirect or sandwaich to detect the interest antigen?

[@anumsiddiqui3986]

When we added the reagent to our sample why not all the GOI get tagged by HRP enzyme..and when we add sample to the plate what are these non tagged antigens that binds with antibody...I m not getting this point?

[@aksharabachu2375]

noice work

[@GordonChao0508]

Does Competitive ELISA first coat antigen to well plate or antibody?

[@sashathomas58]

With reference to RuNs comment " alot of this is unecessary as people will know what an anitbody is" THIS IS RUDE and so very untrue, im glad he illustrated this as sometimes I get the two mixed up ie, antigen and antibody. I was wondeing if you could have videos on competative radioimmunoassay or would you say that the competative elisa is based on the same principls? very good video thanks xx

[@madihakaleem8880]

Its still not clear for me when this experiment would be required. Am I correct in understanding that this can be used to check if a synthesized protein binds similar to a native protein by the antibody?

[@Protocolplace-about]

Sure, it could be used like that. But competitive ELISAs are most often used to simply measure the amount of a certain protein or reagent that is present in an unknown sample.

[@greencard1245]

One like is not enough :-) Even I understand you well! Thanky you :-)

[@reddishcat1]

It is not really needed to bock the plate with BSA or detergent. noting is really going to go wrong. except if it has any influences on a well ratio transfer. what it does not in my opinion.

[@Protocolplace-about]

Thanks for the comment. If you could define "well ratio transfer," that would be great. That's a new term for me. My understanding is that if you don't block the plate, enzyme conjugate could bind to the plate instead of the capture antibodies. Then, you would be measuring a false signal, making you think there is less sample protein of interest than there really is.
As far as I know, the Competitive ELISA will only work well if your sample's protein of interest competes with the enzyme conjugate for a limited number of capture antibodies. Without blocking the plate, both of them could potentially bind the plate instead of the capture antibodies, undermining the assay. Is my reasoning correct?

[@reddishcat1]

Thanks for your reply.
I ask my teacher today before reading this ,and you are completely correct. with "well ratio transfer" I just meant "would the ratio(conjugate/sample) get's good across on the antibody's?" I first thought that this ratio would sit on the antibody, but also on the plate, without any consequence. I was wrong.
But not completely, you could get a somewhat right result without blocking the spots it is not really trustworthy, but still more trustworthy when you do the same to another ELISA kind
anyway, you make great videos. I like the clear simplistic way they look.

[@lelawati23]

If competitive ELISA can be used to detect antigen, when to use competitive ELISA and when to use sandwich ELISA?

[@Protocolplace-about]

In my experience, competitive ELISAs take a little less time, but could be less accurate / sensitive than sandwich ELISAs, and could be more prone to user-error than sandwich ELISAs (especially on the step where you add sample / enzyme conjugates to the competitive ELISA plate). But the reality is that nowadays people typically buy commercial kits from companies and use them no matter what type of ELISA they are, and most kits seem to work pretty well. It usually comes down to price and availability of the kits/reagents that you need to detect whatever it is you are trying to measure.

[@lelawati23]

Thank you !

[@user-yj8bc2mi3d]

happy happy happy (voz de pito)...

[@cformerly]

A lot of this is unnecessary, most people coming for this will already have knowledge of what an antibody is etc.

[@Protocolplace-about]

Thanks for the suggestion. You have a good point, but I'm trying to help people from all sorts of backgrounds understand these concepts, and some may not be as familiar with the key terms as others. Having listened to many scientific talks, I usually appreciate it when people give a brief review of the basic terminology before moving on to more complicated stuff. It just helps everyone get up to speed. In any case, I hope you benefitted from the video! Best of luck to you.

[@xDomglmao]

helped a lot and please stick to your manner of explaining, it's awesome
what I don't get: isn't it possible to get wrong results, e.g. by any chance many more conjugates binding, than proteins binding leading to a wrong guessed ratio?

[@josh3658edwards]

You are assuming a lot. The background info is appreciated :)

[@elia1823]

Thank you