DNA of Kiwi or Onion, what does it look like?

[enigma2924]

We have completed the experiement with both and onion and a kiwi but we never saw any DNA. Or if we did, we don't know what it looks like. Can someone please help our science fair project is due on 2/22/05.

[deleted-71268]

Hi enigma2924-

In order for us to help, we'll need to know exactly what steps you took to conduct the experiment, and how you were planning on visually identifying the DNA. Please also describe anything that seemed unusual that happened while you were conducting the experiment.

Thanks,
-Steve

[shijun]

Hi Enigma2924,

We actually have a project archived on our website that deals with this and please feel free to use it for your reference: https://www.sciencebuddies.org/mentorin ... ?from=Home

I did a quick web search just now and found the following link that will help you:

http://66.102.7.104/search?q=cache:Mp4j ... en&start=1

Please pay attention to the FAQ item: "1. I'm pretty sure I'm not seeing DNA. What did I do wrong?" I've also copied this below:

1. I'm pretty sure I'm not seeing DNA. What did I do wrong?

First, check one more time for DNA. Look very closely at the alcohol layer for tiny bubbles. Often, clumps of DNA are loosely attached to the bubbles.

If you are sure you don't see DNA, then the next step is to make sure that you started with enough DNA in the first place. Many food sources of DNA, such as grapes, also contain a lot of water. If the blended cell soup is too watery, there won't be enough DNA to see. To fix this, go back to the first step and add less water. The cell soup should be opaque, meaning that you can't see through it.

Another possible reason for not seeing any DNA is not allowing enough time for each step to complete. Make sure to stir in the detergent for at least five minutes. If the cell and nuclear membranes are still intact, the DNA will be stuck in the bottom layer. Often, if you let the test tube of pea mixture and alcohol sit for 30-60 minutes, DNA will precipitate into the alcohol layer.

[LindsayP]

HEy! we just did like the exact same project in science except it was the dna of a pea!

u need detergent(dish soap), a pinch of salt(like the size of a dime), alchohol, a strainer, a tecst tube or something like it to hold the mixture in, and a blender

[LindsayP]

oh and u also need some enzyme (meet tenderizer

[LindsayP]

heres what u do,
put 1/4 cup of the veggie (or fruit i guess), 1/4 teaspoon of salt and 2 cup of cold h2o into a blender. blend on high for 15 seconds. the vegatable(or fruitt) soup should be thin.

pour the soup through a strainer and into another container.

How much soup is present is present? add 1/6 of that amount of liquid detergent.(soap) let the mixture set for 5-10 min.

Pour the mixture into a medium test tube or small glass container until it is 1/3 full.

add a pinch of enzymes (meat tenderizer) to the test tube and stir gently. BE CAREFUL! if you stir to hard, u will break up the dna, making it harder to see.

Tilt your test tube and slowly pour rubbing alcohol into the test tube down teh side so that it forms a layer on top of the mixture. Pour until you have the same amount of alcohol in the tube as pea mixture.

The DNA will rise into the alchohol layer from the veggie mixture. You can use a wooden stick or toothpick to get a closer look at the dna.

[LindsayP]

the enzyme breaks the dna into smaller peices from its original 6 foot length.

the detergent takes the dna from microscopic size to macroscopic(you can see it)

the alcohol is used to see through the dna, it widens it.

the dna looks like seaweed sort it kinda floats in the alcohol