Extracting Onion DNA

bryanandsebastian · Post by **bryanandsebastian** » Thu Sep 27, 2007 3:54 pm

Please, I need to verify if the variable in this experiment is the onion and if the controls are the detergent, salt, and alcohol. I also would like to know if I can experment with other fruits or food in this project, because I need data for comparison in order to make graphs or tables which i need for, to make this project. Please answer as soon as possible. I will really appreciate it.

Sincerly,
Bryan

MelissaB · Post by **MelissaB** » Fri Sep 28, 2007 6:38 am

Hi,

Our variable guide here: https://www.sciencebuddies.org/mentorin ... bles.shtml should help you determine what a variable is and what variables you have in your experiment.

In the introduction to the project online, it says that they use an onion because of its low starch content. Thus, you might want to do some research and find out what other fruits or vegetables have low starch content and experiment on those.

bryanandsebastian · Post by **bryanandsebastian** » Tue Oct 02, 2007 5:13 pm

Um.. I'm trying to see what is the control and variable for the experiment in biotechonolgy "Extracting Onion DNA."

-Bryan

geoffbruton · Post by **geoffbruton** » Tue Oct 02, 2007 5:30 pm

Hi Bryan,

Did you go and read the information contained in the Science Buddies Project Variables website that Melissa recommended?

All of the information you need in order to answer your question is right there!

Please either read, or go back and re-read, the information provided. Then, try and reason out which variable is which in your project. If there is something you do not understand, please let us know.

Please post back to the forum with your thoughts, and we'll let you know how you've done.

Good luck!
Geoff.

bryanandsebastian · Post by **bryanandsebastian** » Tue Oct 02, 2007 6:22 pm

My problem is that this project doesn't really give good data to measure ( or at least for the science fair ) so what I decided is, make the suggestion that the project "Do It Yourself DNA" gives the idea of measuring DNA from other products. This is what I want to do. So this is my conclusion:
The dependent variable is the DNA. The independent variable is the different vegetables and fruits, and lats but not least the controlled variables are the amount of salt, detergent, alcohol, weight of the products, and the temperature.

(P.S. I have my teacher's permission to do this)

Thanks for the advice, please answer back ASAP,
- Bryan

geoffbruton · Post by **geoffbruton** » Wed Oct 03, 2007 8:00 am

Hi Bryan,

You've done a great job in determining the variables in your experiment!

Now you need to decide which fruits or vegetables you would like to analyze for your project. You'll notice that the project outline in the Science Buddies Project Ideas explains that strawberries are octoploid - meaning that they have eight copies of their DNA in every cell. Since you are planning on intercomparing different fruits or vegetables, you should probably look into how this might affect your yield, and why.

Also, what mass of fruit and vegetables are you planning on analyzing? You correctly stated that this is a controlled variable, but you will need to determine the masses beforehand and make sure that you use the same amount for each test. If possible, I would also recommend performing multiple tests on the same fruit / vegetable in order to see if there is any variation from run to run.

It looks like you're off to a great start, so please just let us know if there are any specific questions you may have.

Good luck!
Geoff.

bryanandsebastian · Post by **bryanandsebastian** » Wed Oct 03, 2007 3:59 pm

Thank you very much for the answer!

I need to get this information: how many chromosomes does kiwi, green peas, and chicken liver, have? It's ok to stain chromosomes with methylene blue, or can you recommend any other stain? What are the products or food that yield more DNA?

By the way I'm in seventh grade. Thank you again for all the answers Geoff.

-Bryan

geoffbruton · Post by **geoffbruton** » Wed Oct 03, 2007 4:50 pm

Hello again, Bryan,

It sounds as though your project is definitely shaping up! Great work!

Okay, I had a go at trying to find the answers to your questions, and although it took a bit of work (and I certainly didn't know the answers!), the answers are out there! Just as before, go ahead and try typing your question into your favorite search engine and see what you find.

I used Answers.com and Google.com for each of your possible variables and didn't have to go very far. Try varying your keywords and see what you get back...

The Genome News Network (GNN at http://www.genomenewsnetwork.org/resour ... _2_1.shtml) is very helpful with lots of great information.

In addition, the National Center for Biotechnology Information (NCBI at http://www.ncbi.nlm.nih.gov/mapview/) also has a lot of excellent information.

Please do not worry if the vast majority of this information doesn't make any sense - the websites are not aimed at science fair project students! However, they are a great - and scientifically valid - source for the information you are seeking.

I'm afraid that this subject is not really my area, so hopefully another expert who actually works in this field will be able to answer your question as to which is the better stain to use. Could you also please expand upon what you are intending to do with the stain, since this was not in the original experiment.

As for your last question - which foods or products yield the greatest amount of DNA - that is the objective of your project!

Best of luck with your research, and please be sure to post back with how your project is going.

Good luck!
Geoff.

bryanandsebastian · Post by **bryanandsebastian** » Wed Oct 03, 2007 5:50 pm

Thank you so so much for the info. Apparently all the websites you gave us ( thought we have not checked yet ) looks to me we haven't found those. I don't know how you do it but your doing a great job at getting info. By the way it must be so hard work to take your time and search for our answers!

Regarding the stain, my mom works in a lab as a microbiologist and she's gonna try to stain the muccus that contains the DNA. But it's ok she will try to find the answer her self.

I'm gonna put a site for you to see: http://www.funsci.com/fun3_en/dna/dna.htm

THANKS FOR THE INFO,
-Bryan[/b]

geoffbruton · Post by **geoffbruton** » Thu Oct 04, 2007 8:37 am

Hi Bryan,

Glad to be of help! But please don't misunderstand - I'm not *giving* you the answers, I'm just seeing if *I* can find them, and then simply showing you that the information is out there. You are the one doing all of the real work - and doing a great job of it!! Like so many of the Science Buddies Experts, my work often involves researching different subjects - so we often get pretty good at finding things quickly.

Thanks also for the website you provided - I thought it was excellent and I hadn't found that one! A great find with some terrific photographs - which makes me think that perhaps you should try taking some photographs of your work and including them in your presentation.

You are also very lucky that your mom works as a microbiologist - please let us know what you both decide would be the best way to go with the staining part of your project.

Keep up the good work, and please keep us informed of your progress.

Good luck!
Geoff.

bryanandsebastian · Post by **bryanandsebastian** » Fri Oct 12, 2007 3:12 pm

Hi again it's Bryan!

I need to make sure which onion (white or yellow) is better to do the experiment. Another Q. is if I can use 95% Isocropyl Alcohol instead of 95% Ethanol.

Please answer as soon ASAP because we are going to start my project tomorrow ( 10/13/07 ).

-Bryan

geoffbruton · Post by **geoffbruton** » Mon Oct 15, 2007 10:18 am

Hi Bryan,

Glad to hear that you're almost ready to start your experimental phase!

With regards to which type of onion to use (yellow, white or even red or green), I think that is entirely up to you. I have no idea which might contain a greater or lesser amount of recoverable DNA - though this could always be something that you could look into as part of your project! As long as you specifically state *which* onion you analyzed, I think you'll be safe.

As for which alcohol to use - do you mean isopropyl alcohol? (I'm not sure what you mean by "isocropyl" - do you have any more information on this material?) To be honest, I have no idea as to whether or not this will have effect on your results - hopefully someone else in the field will be able to give you a better idea. Is there any reason why you do not / cannot use the 95 % ethanol used in the original paper? This should be readily available to you through your school.

Please let us know your thoughts - and good luck!
Geoff.

Craig_Bridge · Post by **Craig_Bridge** » Mon Oct 15, 2007 4:15 pm

Isopropyl alcohol C3H7OH and ethanol alcohol C2H5OH are both hydrocarbon solvents with an OH ion; however, that is about the end of their similarities in chemical reactions because they are very different molecules.

Without reasearching your process from beginning to end, one can't answer if one can utilize a different alcohol solvent. In other words, you would have to do a considerable amount of experimentation to determine if it makes a difference or not. Since the difference in various alcohol solvents in a DNA extraction isn't your experiment, stay with ethanol.

bryanandsebastian · Post by **bryanandsebastian** » Wed Oct 17, 2007 3:17 pm

We have no 95% ethanol in the stores to use. They don't sell it commercialy. We've seen in other research that they use 91% isopropyl
We've found that the difference is that there is more water in this one. By the way what's the control in this experiment.

The teacher says it should be a known source of DNA to compare to our results. How do we know that what we are extracting is real DNA? We know that the answer is that the muccus we get is the DNA, but she keeps asking us for the control. For example in "which is the best mouthwash" the control is distilled water. Or the control is the experiment itself???

Thanks,
Bryan and Sebastian

Louise · Post by **Louise** » Wed Oct 17, 2007 4:12 pm

bryanandsebastian wrote: We have no 95% ethanol in the stores to use. They don't sell it commercialy. We've seen in other research that they use 91% isopropyl
We've found that the difference is that there is more water in this one. By the way what's the control in this experiment. The teacher says it should be a known source of DNA to compare to our results. How do we know that what we are extracting is real DNA? We know that the answer is that the muccus we get is the DNA, but she keeps asking us for the control. For example in "which is the best mouthwash" the control is distilled water. Or the control is the experiment itself???

Thanks,
Bryan and Sebastian

Hi! In the USA there is a brand of alcohol called "Everclear" which is available as 95% alcohol (190 proof) and 75.5% (151 proof). In some states the 95% cannot be sold, but most states it can. I would see if your parents can buy this at the liquor store. I think the majority of the sales of this brand is to scientists who need 95% ethanol for experiments.

If you are in another country, there is probably something similar.

If you are diluting the ethanol with water, the lower proof may be okay (use less water... post the procedure and someone can help with the math).

I'll let an expert who has been following your thread more carefully answer your question about controls.

Louise

Extracting Onion DNA

Extracting Onion DNA

Didn't really answer the Q........

Thanks!!!!!

THANK YOU SO SO SO MUCH GEOFF

Thanks

Re: Thanks