Protein Analysis: The Bradford Assay & Spectrophotometry

Proteins are expressed from our genetic blueprint to perform specific functions in the cell, and even a small difference in protein concentration can lead to defect and disease. When we perform protein experiments that try to replicate the conditions inside living cells within a test tube, we need to know exactly how much protein is present under different conditions. Today we will build on our previous discussions on protein analysis to talk more broadly about how we can measure protein concentration in any molecular biology experiment using spectrophotometry and the Bradford Assay. All of the techniques we will talk about in this video are used to measure protein concentration before running your SDS-PAGE experiment.
My name is Jack Wang, a microbiologist and science educator, and the 2020 Australian University Teacher of the Year. You can find out more about my work here: jackwang.com.au
Blog entry accompanying this video: jackwang.com.au/blog/applesan...
The equipment I use to make these videos. I will earn a small commission if you purchase using these Amazon Affiliate links, which will be re-invested back into the channel.
Main Video Camera: amzn.to/3NAuqra
Best lens for talking head video: amzn.to/48obmEt
Best lens for B-roll: amzn.to/3tshoVY
Favourite Photography lens: amzn.to/41wStNB
Backup Camera: amzn.to/3Tz8bWv
Productivity Mouse: amzn.to/3tpzOGL
Mechanical Keyboard: amzn.to/3RofA8o
Microphone: amzn.to/47am5kS
Computer monitor: amzn.to/3RwfhZl
Main Key Light: amzn.to/3NCICjr
Accent lighting: amzn.to/3RRPU5E
Our previous videos on protein analysis:
SDS-Page - • Protein Analysis: SDS-...
Western Blotting - • Protein analysis: West...
#biolabcollective #protein #laboratory #science #microbiology
00:00 Introduction
01:21 Absorbance at 280nm
02:07 Nanodrop
04:14 The Bradford Assay
04:56 Conclusion

[@SBRay-ir2cp]

Very clear. Thanks.

[@alisniper797]

Great video! Really helped me with my lab report : )

[@BioLabCollective]

Great to hear - thanks for watching

[@jhustinecardenas9609]

A very helpful explanation, would you be able to talk about the Modified Lowry Method Assay and procedure?

[@osmirod1]

How do I decide the concentration of protein I should load per well when running my western blot? Help!

[@yushi.hoseok]

How much of Bradford reagent should we add?

[@BioLabCollective]

Varies depending on the kit you buy. Should be the same volume of Bradford reagent in every tube, because the variable you are changing is protein concentration

[@SBRay-ir2cp]

Sorry ! Is there some software or algorithm for drawing the standard curve ?

[@BioLabCollective]

Nothing fancy, just Microsoft excel or you can draw it by hand.

[@SBRay-ir2cp]

@@BioLabCollective Thanks very much

[@saharkhalil5483]

My concentration is 0.3952mg/ml how can its calculate its volume to load maximum 50ug of protein per well?

[@BioLabCollective]

We go into this topic here: Laboratory Solutions and Dilutions
czcams.com/video/t2eC_hvaIBc/video.html

[@Jake_M_Warren]

concentration = mass / volume

[@scarletttjaguar]

I like your voice 😅

[@BioLabCollective]

Thanks for watching! Every bit counts for small channels

[@maheenng]

good vid but you did too much cutting while edditing, it seems too fast to understand

[@BioLabCollective]

Thanks for the feedback. Unfortunately slow videos have low watch time and the algorithm downvotes them on CZcams. Will try to make every video better