During gel electrophoresis, DNA molecules can easily be separated...

Question

During gel electrophoresis, DNA molecules can easily be separated according to size because all DNA molecules have the same charge-to-mass ratio and the same shape (long rod). Would you expect RNA molecules to behave in the same manner as DNA during gel electrophoresis? Why or why not?

Accepted Answer

Hello everyone. Let's look at our next problem. It says the D. N. A. Samples in question are placed in the wells in gel electrophoresis. However one of the wells is reserved for a DNA sample that contains DNA fragments of known lengths. This standard reference is called the, so let's recall. Well imagine our gel here and we've got little wells for our samples where they get loaded. Our samples have dye in them and one of these is our reference with fragments and these fragments are of known lengths and therefore they can serve as a reference. So say here's our sample here and it gave a band right there. We can estimate the length of what that band is and we can see when we look at this, what it looks like that. It's easy to recall that what it's called is over here in choice A A DNA ladder because it has the appearance of a ladder. Once it's run through the gel with all these fragments of different sizes spread out, let's look at our other answer choices. Um Choice B. Is probe. A probe would be some sort of labeled um segments labeled primer. That would help you find a specific sequence in your DNA. Um But it's not our reference fragments, not what we're looking for here. So not our answer choice C. D. N. A clone would be, you know, a copy of A. D. N. A segment here so not what we're looking for. And then finally DNA bands um DNA bands are actual samples that we run that we see on our gel. So um that's what we refer to in the DNA bands refer to the sample we're looking at, not our reference standard, so that's why Choice D. Is not correct. Um the D. N. A sample that contains DNA fragments of known lengths as a standard reference is Choice a DNA ladder. See you in the next video.

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During gel electrophoresis, DNA molecules can easily be separated according to size because all DNA molecules have the same charge-to-mass ratio and the same shape (long rod). Would you expect RNA molecules to behave in the same manner as DNA during gel electrophoresis? Why or why not?

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