Polymerase Chain Reaction (PCR) & Gel Electrophoresis

Working with DNA is the bread and butter for molecular biologists, and PCR is one of the most common techniques in the lab. Today we will examine Polymerase Chain Reaction by walking through and explaining an interactive PCR experiment step by step in the lab. In this example, we are working with a new bacterial strain, which may be resistant to many different antibiotics. We can extract genomic DNA from the bacteria and run a PCR to see if we can detect any antibiotic resistance genes in its genome. We can then visualise the PCR products through gel electrophoresis.
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
The blog post accompanying this video: jackwang.com.au/blog/signalvnoise
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.
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#biolabcollective #pcr #science #teaching #laboratory #dna
00:00 Introduction
00:59 PCR ingredients
02:37 Mastermix calculation & preparation
04:02 3 phases of PCR
04:59 Gel electrophoresis
06:39 Loading the gel
07:42 Interpreting results

[@fatcammal]

This is THE most thorough and effective PCR video i've ever seen

[@BioLabCollective]

Thank you so much! Glad it helps

[@ronitdey8099]

This is exactly what I was looking for! Thank you sir for this masterpiece!!

[@BioLabCollective]

Thanks for watching!

[@luissantos2355]

the level of production is amazing. how do you not have more views?

[@BioLabCollective]

The algorithm is tricky to figure out, but glad you were able to find the channel!

[@siasmith6746]

this is the clearest, most precise video I have seen on PCR. I normally do not comment but this was phenomenal

[@siasmith6746]

I am a subscriber now, all of your videos are made with such care.

[@BioLabCollective]

Thank you! Took a long time to make, glad the effort shows on screen

[@NaveenKumar-it3gq]

Thank you for the simplified lesson. Keep up the good work.

[@BioLabCollective]

Thanks for watching and commenting!

[@emmadegroote4014]

Thank you, this helped sooo much!!! You're videos are amazing!

[@BioLabCollective]

Glad they help - thank you for taking the time to comment!

[@freespirit6855]

Do we need serial dilution for running a PCR?

[@BioLabCollective]

Not always, depends on what you are trying to dilute out? Same principles apply when you are setting up your PCR mastermix and diluting it out for the different reactions.

[@skazka3789]

Hello again Professor!
With regards to the PCR, the machine says there is an amplification in my negative controls. But the CT values for the negative controls are consistently 10 points higher than the CT values for the actual samples. For example CT value of 37 for negative control vs CT of 21 for the sample. These results are still fine yeah?

[@BioLabCollective]

I'm not really sure about your experimental context so can't really say by CT values alone. Have you run the samples on a gel to assess the size of the bands? Probably the next thing to try

[@InquilineKea]

OH THE COMB CREATES HOLES IN THE GEL

[@BioLabCollective]

The gel lanes (or holes) need to be standard sizing all the way across - a comb makes that happen more or less