Creating an SDS-PAGE Molecular Weight Standard Curve in Excel

In this video, I show you how to measure the migration distance for each lane, and how to use that information in Excel to create a standard curve. From there, we're able to calculate the molecular weight for any protein on our SDS-PAGE gel.
00:24 Measuring migration distance
01:27 Calculations in Excel
02:02 Creating a scatter plot
04:24 Estimating molecular weight of any protein band

[@danbram999]

Best video I have found all day on youtube, been stuck on a university course work piece all day, thank you! This has saved me! :)

[@loladify]

Didn't understand what to do. This explanation is the best

[@BiochemTv]

Glad we could help!

[@christophersun9519]

Life Saver. I could not understand how to create this curve for the life of me. Thank You

[@luisma7290]

I am from Mexico, and a did not find information in Spanish about this, thank you, thank you so much for this video.

[@monkeymeme911]

You are the best! And your voice is very nice, easy to understand.

[@morganphillips8609]

You are a godsend. Thank you very much, you are so clear and easy to understand.

[@DCJellybean]

Thank you so much....explained it so much better than my lecturer :D

[@ChrisRyot]

I was just browsing through some of the links I saved during my time at university and found this one, which really saved my ass back then :D I still don't really understand it but it got me a good grade and I'll never have to use it in my job anyways so, yea. Thanks mate :)

[@BiochemTv]

Glad I could help!

[@mariammusri5640]

saved my life XD! Thank you so so much! So easy to follow and well explained and edited.

[@ChrisRyot]

Incredibly helpful, thank you! You saved me.

[@furulund]

You save me, thanks!

[@jayshap.2892]

Not sure if you gonna see this, But thank you so much. To be fair my professor explain it to me just like that but just could not get it untill now

[@lanceenglish6556]

Hi Jaysha, I appreciate it! Glad it helped!

[@bosmer2907]

Extremely helpful! Thank you!

[@sebastianoarcangeli80]

Great video! Why did you use the log of MW and not directly the MW?

[@BiochemTv]

It's pretty much the "industry" standard. You can plot it directly to MW, but then you would have to fit it to a log curve instead of a simple line.

[@ahmedeid2340]

Many thanks for your efforts, the best video at all

[@olandhamiller9875]

Thank you soooo much for this video!!

[@youssifimbarak6522]

thank you very much for this video you saved our life :) keep up the good work

[@alicebrown3124]

Thanks for the wonderful and conscise information

[@narjis3950]

very helpful :) i was stuck on my biochem lab report

[@Nomamzaza]

well explained, thank you so much

[@carlywang3136]

So thanks :) You saved me 2% of this stupid uni assignment.

[@BiochemTv]

If it involves proteins and Excel, it can't be too stupid! :)

[@DeborahKuo]

you totally saved me! great video.

[@alicebrown3124]

Thanks for the wonderful and conscise information I

[@dankesdlorien3857]

you've saved my life

[@hanez5786]

How do you find the molecular weight?

[@animeandstuff5377]

For all the future people who aren’t the sharpest knife in the drawer the 31.31 is MW

[@houthailjammas8199]

I think you should caculate the releative mobility: protein distance/stain distance

[@BiochemTv]

You should. But as long as your tracking dye runs straight, this method works fine.

[@houthailjammas8199]

@@BiochemTv thanks for reply Is it important that the standard curve equation should be linear, could i use logarethmic equation if the r2 was higher with second one

[@JYLfighter]

Shouldn't the y axis be retention factor ? Or it's ok to use just migration distance without calculation the Rf value ?

[@BiochemTv]

For molecular weight determination using a single gel, migration distance is fine.

[@JYLfighter]

biochemTV in what case we need Rd?

[@BiochemTv]

From what I understand, Rf is useful when comparing bands on different gels. I can't speak from experience, because I always run a prestained protein standard on every gel I run.

[@BadAtPickingUsername]

nice vid my friends andreea and cam really enjoyed it

[@violindalola]

Nice! Thank you!

[@georgiamillis4218]

Thank you!! Lab report due tomorrow :p

[@meaayusha]

Thank You Heaps!

[@elizafletes3769]

How do you find Relative Mobility?

[@yamkelabotman1709]

Did you eventually find out coz I wanna know too

[@SarahMMorsy]

very very helpful, thank you

[@hedieten82]

thank you, legend!

[@lukash.8788]

You are my hero

[@rojalinkhatua3614]

thanks it helped me a lot

[@lisachim4474]

THIS IS AMAZING! THANKYOU

[@durrotunekhaannuur4556]

Hi I work with this but it failed. I tried and tried but still doesnt work. Hw about the Rf?

[@lilwadd91]

Thank you so much!!!

[@BiochemTv]

You're welcome!

[@mulfah18]

thank you.. very helpfull

[@nothere890]

Beautiful!

[@BiochemTv]

Thank you!

[@HemapriyaKothuruChinnadurai]

Which ruler you have used for measuring the migration distance

[@everagustini2346]

Thank you!

[@solakhalid8967]

In this case do not need calculate protein concentration by badford test?

[@bobu5213]

So the relation between these variables is always inverse linear?

[@srushtypatil7436]

The Rf value is mentioned, but I didn't get how the volume (area under curve) could be calculated ?

[@roshnirajesh1940]

I do not get how migration distance is on the x- axis (independent variable). Isn't migration distance dependent on the size of the DNA? Then wouldn't the distance be on Y-axis and log of molecular weight on X-axis?

[@muhammadabdillah8363]

thank you for your Video. i have a problem. my R^2 is 0.9739 and y= -1.3068x +2.2759. i have a migration band at 1.05 cm in 100kDa and its Log MW should be 2. But this is the problem. my protein migration shows same as my marker 1.05cm. after i input into equation its not same as my marker, its shows 115kDa. and this happening in all my protein migration. it'd blowed my mind in this day. thank you verry much.

[@anonymous672]

awsome!

[@Daiiia0212]

Thank you so much, I have to present a report rigth now, you save me, but does exist a software that can do it ?

[@BiochemTv]

You're very welcome. I use Adobe Illustrator to make the measurements, but any vector graphics software will work. Inkscape is a good open source alternative.

[@herrwolken]

wouldn't a logarithmic trend line be the better choice? your R² is only at 0.98xxx. a ln-trendline would rise it to 0.99xxx.

[@BiochemTv]

If you swap the axis (plot migration distance vs. molecular weight), then a log trendline would work just fine. But you should still get an R² = 0.9804. If you plot migration distance vs. molecular weight (like in the video), you could use an exponential trend line. What equation did you get for the logarithmic trend line?

[@siwonsarmpithair1920]

how can we add the logarithmic trendline?

[@TheQuiksniper]

Thank you

[@thesuperproify]

you saved me,

[@UpasanaS]

How to get the linear equation to calculate?

[@Nomamzaza]

when you plot the standard curve on excel you must click on the option "display equation on chart"

[@June-oe6rx]

but why do we use linear line? why not others?

[@geanarcos6509]

but how did you get the MW

[@lyeerg9896]

that is given to you with the ladder. It comes from the manufacturer

[@MyMalachi2010]

How would one calculate MW if it isn't given?

[@lyeerg9896]

that is given to you with the ladder protein, which comes from the manufacturer

[@amisiato9350]

You just save me

[@boonga585]

3:46

[@wulwulanlan2223]

Thankyou so much =^.^=

[@smol578]

CHAD

[@homo1170]

thank you!!! u really saved me!!!

[@danieldimitrov3146]

Thank you!