DNA - Extraction and Yielding

[girlsaloud]

I was just inquiring if anyone who has the knowledge in Biochemistry or who understands the basics of DNA could help me.

 

I wanted to know why different sources of DNA yield out different amounts of DNA. I've tried the extraction process http://learn.genetics.utah.edu/units/activities/extraction/

 

But I was hoping to justify why. I understand that different contents in comparing with Banana, Broccoli, Strawberries and Kiwi Fruit all yield various amounts of DNA.

 

My thoughts are that they have different content of carbohydrates, proteins, water and fats which alter the amount of DNA. But I'm only limited to that for the moment, could anyone emphasize to a further extent?

[CharonY]

Well.. different yield based on what? Weight of the sample? Different cells for instance have different weight to DNA ratios.

Or some cells/tissues are harder to disrupt (and so on and so forth).

[girlsaloud]

Based on different sources. The experiment used Broccoli, Banana, Strawberry and Kiwi Fruit (as they were recommended to be good DNA sources) and we received significantly different amounts.

 

I was wondering why they were so different, even though the amount of the sources were the same and the whole experiment was done the same.

[ecoli]

Using that procedure it would be kind of hard to tell how much DNA you have.

[girlsaloud]

It's not exactly finding every minute amount of DNA, just a simple high school expirement based on what we can pull out (with a hook stick). But successfully gaining DNA and weighing with a sensitive weight machine.

 

I'm trying to justify why Banana gets more DNA compared to Broccoli. One of my theories is the amount of Water content, and the amount of fats, proteins etc..

[CharonY]

Based on different sources.

No, I meant per what unit. Do you get less DNA for example from 1g Broccoli as compared to 1g Banana?

There are a lot of reasons and one question is to what you have standardized your yield.

Common examples are different effectiveness of cell disruption, higher weight of the tissue (e.g. water content as you mentioned) and so on.

The basic thing to keep in mind is that you usually only have one copy of the genome per cell. Only if you disrupt the same amount of cells you will get equal yields.

[ecoli]

also, it would depend on what stage in the life cycle... DNA replicated before cells divide, so in a high period of growth, you're going to get more DNA.

[girlsaloud]

Thanks guys for helping me out! Good karma too you ;D