Does all DNA look the same? PLEASE HELP QUICK!!!

[zarae]

Hi
I was looking at the Project Ideas part of this site and one that particularly interested me was the one about extracting DNA from an onion. I was wondering how I could expand on this a little and I thought maybe if I took DNA from several different types of onion, e.g. spring, red, brown, etc. I could see if there was any visual difference between them. However, I'm only 12, and know very little about DNA apart from what those letters stand for, the basics of what it is, its double helix shape, and that it is microscopically small. (Which is another thing, just how small is DNA? The highest magnifying microscope I can get hold of can only magnify up to about x200. I highly doubt this is enough to see the DNA, but thought I would check anyway?) So, does all DNA look the same? I don't think there is any point me doing this experiment if any-one who knows anything about DNA could immediately tell me that all DNA does look the same. Any info would be much appreciated as soon as possible, since I am on a very limited time frame.

[deleted-71487]

Well, DNA is way too small to see with a microscope (except perhaps for certain exotic ones).

However, there's a technique called electrophoresis that isn't too hard to do (I did it in a science class over at Caltech when I was in junior high).

What that does is seperate out DNA across a gel so that you can dye it and see stripes that indicate the DNA sequences (well, more or less).

I don't know whether different types of onions would be different enough to show up with this technique, though (you might have better luck asking in the life sciences forum).

Anyway, if this interests you, I would suggest googling for "electrophoresis" and there are lots of pages that talk about how it's done and what you can do with it.

[zarae]

Yeah my teacher told me about that as well. I took your advice and ran a Google Search on it and came up with some really interesting things. My school doesn't have all the equipment to do it, but my teacher said if I can write up a really good aim, hypothesis and method, and prove I'm capable of doing it, they will try and get in from other schools the equipment we're missing. I want to compare the DNA from two different types of onion (I'm thinking maybe red and brown, because they're apparently they're quite similair, if you know of two different kinds that would be better, please say). How would I measure similarities/differences, and how could I write a hypothesis for this? Thanks for your help.

[zarae]

By the way, I live in New Zealand and I have no idea what age junior high school is. Are you sure its safe for some-one my age, because it says that the stuff you use to dye the DNA can damage your DNA if you touch it and the UV rays you use to see the DNA fingerprint (I'd also really like to know if that is the correct terminology) at the end can damage your eyes.

[deleted-71552]

Hi
I was looking at the Project Ideas part of this site and one that particularly interested me was the one about extracting DNA from an onion. I was wondering how I could expand on this a little and I thought maybe if I took DNA from several different types of onion, e.g. spring, red, brown, etc. I could see if there was any visual difference between them. However, I'm only 12, and know very little about DNA apart from what those letters stand for, the basics of what it is, its double helix shape, and that it is microscopically small. (Which is another thing, just how small is DNA? The highest magnifying microscope I can get hold of can only magnify up to about x200. I highly doubt this is enough to see the DNA, but thought I would check anyway?) So, does all DNA look the same? I don't think there is any point me doing this experiment if any-one who knows anything about DNA could immediately tell me that all DNA does look the same. Any info would be much appreciated as soon as possible, since I am on a very limited time frame.

May I suggest that you post this help request to the Life, Earth, and Social Sciences forum? The folks that monitor that forum are probably the right folks to ask about this subject.