P: 12 DNA Extraction


Introduction:

Deoxyribonucleic acid DNA is a nucleic asid that encodes the genetic instructions used in the development and functioning of all known living organisms and many viruses.
Nucleic acids compose the nucleo base( G,T,C,A ) complements G-C  A-T unid base nitrogenous
Within cells, DNA is organizet into structures called chomosomes.

Objectives:

1 Study DNA structure.
2 Understand the prosses of estracting DNA from a tissue.

Materials:

1L Erlenmeyer flask
100ml beaker
100ml graduated cylinder
Small funnel
Glass stirring rod
10ml Pipet
Knife
Safet goggles
Cheesecloh
Kiwi
Pineapple juice 1ml-5ml
Distiller water
90% Ethanol ice-cold
7ml DNA buffer
15gml dish soap
15NaCL
900ml tap water

Procedure:

1. Peel the kiwi and chop it to small piece
2.Add 8ml of buffer to the beaker
3.Mash the kiwi puree carefully for 1 minute without creating many bubbles
4. Filter the mixture
5.Add beaker contain carefull on top of the cheesecloth to fill the graduated cylinder.The juice will drain through the cheesecloth but the chucks of kiwi will not pass through into the graduated cylinder.
6. Add the pineapple juice to the green juice .This step will help us to obtain a pures solution DNA. Pineapple juice contains an enzyme thet breaks down proteins.
7. Tild the graduated cylinder and pour in an equal amount of ethanol with an automatic pipet.Put the ethanol through the graduated cylinder very carefully.You will need about equal volumes of DNA solution to ethanol
8.Place the graduated cylinted so that is eye level .Using the stirring road,collect DNA at the boundary of ethanol and Kiwi juice.Do not stir the Kiwi juice: only stir in the above ethanol layer
9.The DNA precipitatee looks like long,white and thin fibers.
10.Gently remove the stirring rod and examine what the DNA look like.



Questions:

1 What did the DNA look like?
1 White filaments that were precipitated in the ethanol.
2 Whty do you mash the kiwi ? Where DNA is located inside the cell?
2- To break the cells and remove the DNA that is  found in the nucleus of the cell
3 Explain what is the fuction of every compound of the buffer"soap and salt"
3- Salt is hypertonic medium that produces the break of the cell's membrane.
 Add soap extrain the proteins
4 DNA is soluble in water , but not in ethanol.What does this fact have to do with our method of extraction?
 4- When DNA comes into contact with ethanol it precipitates out of solution so you can see it forming in the clear layer above the kiwi solution. That is what I saw in the experiment