Extracting DNA from onions

Dr : Tahsin ShoalaEMAN Mohamed

-ALL OF US KNOW THAT “ DNA” , OR DEOXYRIBONUCLEIC ACID, IS THE HEREDITARY MATERIAL IN HUMANS AND OTHER ORGANISMS INCLUDING

PLANTS.

-MOST DNA IS LOCATED IN THE CELL NUCLEUS (WHERE IT IS CALLED NUCLEAR DNA) , BUT A SMALL AMOUNT OF DNA CAN ALSO BE FOUND IN THE MITOCHONDRIA (WHERE IT IS CALLED MITOCHONDRIAL DNA OR MTDNA).

Perface

DNA is surrounded by nuclear membrane , cell membrane and cell wall ,as well, in plant cells.

-I Observed that:

1 -DNA is found in the nucleus of membrane-bound cells. The membranes are lipid and protein in composition. It could be broken down using laundry detergent. 

2 -DNA is a polymer made up of repeating chains of nucleotides. The sugar and phosphate components of DNA (the backbone) are both readily soluble in water.

Cont

3-The phosphate groups on the outside of DNA carry a negative charge. These negative charges are attracted to and are neutralized by cations such as sodium. When sodium is added to DNA it forms a protective "shell" around it. On the other hand, protein molecules precipitate from solution in the presence of salt.

4 -DNA is insoluble in ethanol (ethyl alcohol). As ethanol is added to a solution containing DNA, the DNA will come out of solution and stick to whatever is around.

Hypothesis

" If I could mix DNA with NaCl salt , Ethanol and laundary detergent Then i could extract

DNA and see it clearly“.

-And from this point I decided to conduct an experiment to extract the DNA from “Plant tissue”

-I choose “Onion” for my experiment as its cost , abundance and low starch content .

Apparatus

1 -Onions . 2 -Ethanol.

3 -Dish washing liquid . 4 -NaCl Salt.5 -test tubes .

6 -Beakers .7 -Water.

8-cutting board / funnel.Water bath. 9-

10 -knife.11 -blender.

procedure# I do procedure as indicated in the picture …

conclusion

I could extract DNA as indicated : Now