DNA Extraction

Start with the cells

• We will use DNA found in the cells in your mouth.

• Use the cup of salt water. Swirl the salt water in your mouth for 30 seconds.

• After 30 seconds spit the salt water back into the cup.

Why do we swirl the salt water in our mouth?

• The swirling separates the CELLS from each other and away from your mouth.

In a graduated cylinder measure 5mL soap, pour into test tube.

Cover the top of the test tube with your hand. Rock the mixture GENTLY for 2-3

minutes

What does the detergent do?

• Each cell is surrounded by a cell membrane

• DNA is in the nucleus of a cell, which is also surrounded by a membrane

The membranes must be broken open in order to get the

DNA out of the cell

Detergent:

• Breaks apart membranes by attaching to the lipids (fats) & proteins in the membranes

The cell and nuclear membranes have been broken apart,

as well as all of the organelle membranes,such as those around the mitochondria and

chloroplasts.So what is left?

• Proteins • Carbohydrates (sugars) • DNA

Add a pinch of meat tenderizer to the mixture

Why?

• Meat tenderizer is an ENZYME– A protein that helps chemical reactions

happen more quickly

• The enzymes in meat tenderizer break apart proteins

The DNA in the nucleus is surrounded by proteins

The meat tenderizer cuts away the proteins from the DNA

Stir very, very GENTLY!

Tilt your test tube & slowly pour a layer of alcohol on top of the cell

soup mixture

• DNA will float

up into the alcohol