DNA in fruits

Today we have an experiment on DNA in fruits. It is really interesting and fun as we can see how a fruit DNA looks like. It is my first time seeing a real DNA and an experience that I will never forget.

3 Thoughts:
1) I have learnt that DNA stands for Deoxyribonucleic Acid and it is the genetic material of cells that is made up of double strands. The double strands will then form a helical structure.
2) I learn that we have to break the physical membranes that enclosed the cells, in other word lyse, to release the nucleus by adding dishwashing detergent to the mashed fruit. The detergent will then cause the cell membranes and those surrounding the nucleus to be degraded.
3) Adding ice cold 95% ethanol in the final step of the experiment is very important because enzymes have to be protected from degrading (reducing the amount of) the DNA at that point.

2 Questions:
1) What if we add in too much detergent to the mashed fruit? Will there be any effects?
2) Why is table salt also added to the mashed fruit?

1 Useful application:
1) Since we know the steps to extracting DNA, we will be able to try out the extraction of DNA in fruits by ourselves at home. Some people may not have a chance to see how a fruit DNA looks like. Hence, we can carry out the experiment and show it to them.

(Extractions of DNA)
   

Sources: Google Images