<p>I’m trying to extract enzymes from a pineapple so I can study how heat, pH levels, UV rays, etc…affects it. Does anyone know how to do the extraction part? Is extracting enzymes from a pineapple the same procedure or the same thing as extracting its DNA??? I’m really confused. 
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<p>No, extracting enzymes is not the same as extracting DNA. If this is a school assignment, didn’t your teacher give you a procedure?</p>
<p>No, this is for a science project so I have to develop or find a procedure myself. Does anyone know how to extract enzymes from a pineapple (or any other living thing, etc.)?</p>
<p>What kind of equipment do you have? </p>
<p>I extract DNA all the time at the lab I work in, involves pipettes, centrifuges, different solutions, etc.</p>
<p>I don’t have very sophisticated materials like centrifuges. I found an easier way to extract DNA from stuff like peas, etc. What I wanted to do was expose the extracted DNA to ultraviolet radiation via a UV lamp to see how it affected the DNA. So I’d compare what the DNA was like before exposure to ultraviolet radiation and after. How can I make the comparison? Am I supposed to look through a microscrope or what?</p>
<p>Did you do a google search? </p>
<p>I’m afraid the problem you’re having is that you don’t have enough science background to even ask the right question. I suggest you do some reading in a basic biology text to understand the difference between DNA and an enzyme. I’ll give you a hint, an enzyme is a protein.</p>
<p>Anyway, Google would lead you quickly to some solutions, so I’m surprised you are even asking the question.</p>
<p>The DNA you extract in a home-made lab is denatured. My daughter did a middle school project where she extracted DNA from onions but her mentor (a biology PhD at a Fortune 500 company lab) said that she could not do anything with it after she extracted it because it was basically dead. I am not sure what ultraviolet light would do other than shrivel it up! Did you run this idea past your science teacher?</p>
<p>What I meant was that DNA wraps around enzymes in a cell. So where would the procedures to extract either one from a fruit or something differ? I’m working with a former Caltech scientist. I should ask him now.</p>
<p>if you do a search for “simple enzyme experiments” you will hit upon a utoronto site which should suit your purposes</p>
<p><a href=“http://www.zoo.utoronto.ca/able/volumes/vol-6/10-miller.pdf[/url]”>www.zoo.utoronto.ca/able/volumes/vol-6/10-miller.pdf</a></p>
<p>UV radiation induces the formation of pyrimidine dimers in DNA (not a good thing for humans obviously). How you plan to visualize this I don’t know. Tell the person you’re working for to hook you up with some equipment!</p>
<p>But norcalguy - does it UV radiation have this effect on the dead, gooky threads that KIDS get when they do the famous “DNA extraction” science project available over the web? I kinda doubt it, but I am no scientist. However, as I said above, the scientist my kid worked with said that there was no point in doing further experiments on the threads since they were dead. Now, if she DID use a centrifuge, maybe some sort of experiment could be run on THOSE bits of DNA. I’ll bow out now - as I said, I am no scientist.</p>
<p>I fail to see how “denatured” DNA qualifies as dead. If anything, it makes it easier to work with. Remember, our cells have to denature their DNA before it can be replicated, transcribed, etc. Renaturation of DNA is also spontaneous so all you have to do is cool the DNA down to get it into duplex form again. Whether denatured DNA is useful depends on the experiment you’re working on. </p>
<p>Now, the DNA that kids typically extract is probably not of the best quality (but not because it’s denatured) simply because it’s not pure. I spend roughly 3 hours at a time going through a 30 step procedure just to isolate the extracted DNA so it can be used for PCR.</p>
<p>As for the OP, I would love to hear what the scientist you’re working with has to say about separating DNA from histones (the enzyme it wraps around). I don’t recall any steps that I perform in my lab that actually directly disengages the DNA from the nucleosome.</p>
<p>Extraction of DNA basically consists of two components:
- Lyse the cell to expose the mess of crap that’s inside.
- Isolating the DNA from the other junk.</p>
<p>Time out, folks. I think it’s time for a molecular biology lesson. </p>
<p>Native DNA, in a cell, is in a complex structure called a chromosome, which will have protein associated with the DNA, lots of tertiary structure (complex folding of the chains) and so forth.</p>
<p>One can extract DNA by doing chromosome preps, but that’s beyond most HS kids, as you need an ultracentrifuge with pre-formed gradients etc. So instead, most DNA preps remove the protein by various means, leaving intact DNA that’s then precipitated out of the solution. These are not normally denaturing conditions for DNA, but they are denaturing conditions for protein.</p>
<p>Denaturing DNA separates the two complementary strands and normally takes high salt concentrations or elevated temperature. Keep in mind, also that denatured DNA can be reannealed back to its double strand state, and can be copied as single strand DNA. That’s the basis for PCR, cycling beteen native and denatured DNA, doubling the amount each cycle.</p>
<p>Norcalguy, I would not characterize the process of DNA replication as involving denaturation, as you probably know. It is a localized melting.</p>
<p>Correct. The DNA is not entirely melted during replication but my point is that in many cellular processes you have to separate the two strands. Therefore, I don’t see why denatured DNA is so bad. All you have to do is cool it down to get it to rehybridize again.</p>
<p>you also must use protease to lyse the proteins, then an aclohol solution to isolate the DNA</p>
<p>Norcalguy, I see what you mean. It’s interesing how robust DNA is, as long as it is not exposed to shearing forces. I did much of my dissertation work on mRNA, which is so labile it seems to vanish on its own. Of course no one works on mRNA any more if they can avoid it - copy the mRNA to DNA and blast away.</p>