DNA Extraction activities/extraction/

DNA Extraction Purpose: To remove the DNA from the nucleus of pea cells. DNA- “The Stuff of Life”; DNA is the blueprint that tells us what we are and how we are made. Nucleus- The control center or brain of the cell.

MATERIALS Dried split peas Dishwashing detergent Isopropyl alcohol Meat tenderizer Small cup or beaker Spoon

Procedure Fill your cup 1/3 full of “pea soup” Put one small spoonful of liquid detergent in the cup with the pea soup and gently swirl to mix. Let the mixture stand 10 minutes. Pour the mixture into a test tube about 1/3 full. Add a pinch of meat tenderizer to the test tube, swirl very, very gently.

Procedure cont. Tilt your test tube and slowly pour rubbing alcohol into the tube down the side so that it forms a layer on top of the pea mixture. Pull out a small sample of the DNA (the snotty substance on the top of the test tube) and examine it under the microscope.

Start with the peas

Blend the peas with water and a little salt until you have “pea soup”

Why do we blend the peas? The blender separates the pea CELLS from each other

Put the strained pea soup in a cup Add a squirt of dishwashing detergent

Let the mixture sit for 5 minutes

What does the detergent do? Each pea 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 cup & slowly pour a layer of alcohol on top of the pea soup mixture DNA will float up into the alcohol from the pea soup

Conclusion What was the purpose of today’s lab? Describe, in three steps, what we did to achieve our purpose. What did you observe while looking at the DNA under the microscope?