What is gene isolation in a way that a middle schooler would understand?

Need answers for a research project...HELP!What is gene isolation in a way that a middle schooler would understand?
It can be summed up as: tiny piece of DNA is isolated by very advanced genetic procedures that are beyond middle school level. And this tiny piece is then ';amplified';' or ';quieted'; depending on what the geneticists want to use it for. They are amplified or quieted by a process called Polymerase Chain Reaction, or PCR.





THe way that the DNA is isolated is tough to explain... say the DNA you want to isolate is prokaryotic... you can use a eukaryotic Piece of DNA to cleave the strand of DNA at the right spaces and splice out all the junk that isn't needed (junk is called introns in genetics). leaving the part that you need. Its VERY advanced for middle school science though, so simplify this as much as possible. What is gene isolation in a way that a middle schooler would understand?
Well, there is the process of cloning a gene and there is the process of finding which gene performs what function. Both might be called gene isolation.





If you clone a gene, then you know what the piece of DNA is that you are interested in, or at least you know something about it at a molecular level. Maybe not the exact sequence, but related sequences, and something about the way it functions. For example, you might know that a particular gene helps an organism take up nitrogen from air and turn it into a more biologically useful form like ammonia. This is nitrogen fixation. And you might know the protein that is responsible for that, and you might have several DNA sequences from different organisms with that particular gene that you can compare. Usually the sequences are similar. You could use that info to try and isolate the gene from a different organism, one where that has not been done before.





On the other hand, you might want to know what causes a particular disease that you know runs in families and might be caused by a specific gene that is carried by certain individuals. That would be a tougher road to go down, but it's typical in research and that too would require gene isolation. In that case case you end up doing a lot more work to try and find a way to identify the protein coded for by the gene. You need to have some specifics about how it causes disease, where it functions, how it functions. It's a much more complicated story.





Here a re a few references. Let me know if you need more detail.

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