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Electrophoresis
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Electrophoresis
Hi! I am a researcher in Pasig City Science High School, currently in 11th grade, and our adviser suggested a study that involves extracting the pure substance of a plant extract and electrophoresis. Our group, being the amateurs that we are, are terribly unfamiliar with the procedures and would like to ask for a bit of background on electrophoresis and what does it actually do. Any feedback from you would be very helpful and is much needed. Thank you.
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SciB
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Re: Electrophoresis
Hi, and welcome to scibuddies.
Electrophoresis just means using an electric current to move biological molecules. There are basically two kinds of electrophoresis [let's abbreviate it to EP] that we use in the lab--one for DNA molecules and one for proteins.
DNA molecules have lots of phosphate groups attached to them and this gives the molecule a net negative charge. According to the laws of electrochemistry, when you apply an electric current [DC, not AC!] to a solution containing negatively charged particles [ions] they will migrate towards the positive electrode. This is how pieces of DNA are separated by EP.
In terms of instruments, equipment and the stuff you need to actually do EP, this is covered very thoroughly online. In simple terms, DNA is separated by putting it into a gel made from a seaweed product called agarose and applying a direct [DC] electric current with the positive electrode located at the END of the gel. The movement of electrons in the current will pull the DNA fragments down the gel, while the thickness of the gel will slow them down through a sort of molecular friction.
Large DNA fragments will move slower than small ones, so as the fragments continue running through the agarose gel, they will gradually become separated and can be identified in several ways.
That's DNA EP. Protein EP is the other commonly used method and it uses a gel too, but this one is made of a kind of plastic called acrylamide. Proteins are much, much smaller than DNA molecules and thus the gel that you use to separate them has to have much smaller pores than agarose. Otherwise,the method is pretty much identical, although the apparatus is different.
That's probably enough information for now. I don't want to overwhelm you with too much all at once.
EP is one of the most commonly used methods in the lab and once you understand how it works, it becomes perfectly logical and understandable. There are many other ways to separate molecules in chemistry and biology and as you progress in science you will become familiar with them and they will make sense.
Sybee
Electrophoresis just means using an electric current to move biological molecules. There are basically two kinds of electrophoresis [let's abbreviate it to EP] that we use in the lab--one for DNA molecules and one for proteins.
DNA molecules have lots of phosphate groups attached to them and this gives the molecule a net negative charge. According to the laws of electrochemistry, when you apply an electric current [DC, not AC!] to a solution containing negatively charged particles [ions] they will migrate towards the positive electrode. This is how pieces of DNA are separated by EP.
In terms of instruments, equipment and the stuff you need to actually do EP, this is covered very thoroughly online. In simple terms, DNA is separated by putting it into a gel made from a seaweed product called agarose and applying a direct [DC] electric current with the positive electrode located at the END of the gel. The movement of electrons in the current will pull the DNA fragments down the gel, while the thickness of the gel will slow them down through a sort of molecular friction.
Large DNA fragments will move slower than small ones, so as the fragments continue running through the agarose gel, they will gradually become separated and can be identified in several ways.
That's DNA EP. Protein EP is the other commonly used method and it uses a gel too, but this one is made of a kind of plastic called acrylamide. Proteins are much, much smaller than DNA molecules and thus the gel that you use to separate them has to have much smaller pores than agarose. Otherwise,the method is pretty much identical, although the apparatus is different.
That's probably enough information for now. I don't want to overwhelm you with too much all at once.
EP is one of the most commonly used methods in the lab and once you understand how it works, it becomes perfectly logical and understandable. There are many other ways to separate molecules in chemistry and biology and as you progress in science you will become familiar with them and they will make sense.
Sybee