DNA Extraction of Wheat Germ and Cheek Cells

DNA Extraction of Wheat Germ and Cheek Cells

What is DNA? • DNA=(deoxyribonucleic acid) • DNA’s = structure consists of a sugar/phosphate backbone to which nitrogenous bases are attached. • Bases = Purine or Pyrimidine ring’s.

NUCLEOTIDE: Sugar. Phosphate, Base

Sugar/Phosphate Backbone

Purine Structures Double circles/ large

Pyrimidine Structures • LOOKS like a “Pie” /single circle/ small • Both Have “y” in name (Cytosine/Thymine)

DNA Extraction using Wheat Germ • Basic procedure: Lyse (bust) wheat germ cells • Rupture cell walls, membranes and nuclear membrane to release DNA

Materials for DNA extraction: • • • Raw Wheat Germ Warm water bath (50°- 60°C) Ethyl Alcohol (cold) Liquid detergent (Woolite, Dawn, Palmoliv) 2 50 ml beakers 1 Graduated cylinder (large) Glass stirring rod/ wooden stick/spaghetti paper towels Thermometer and Hot plate

Obtaining a Wheat Germ Solution • Prior to beginning the extraction, turn on hot plate and prepare the warm water (50°- 60°C). • The heat softens cell membranes and the nucleus & inactivates enzymes that would cut the DNA into pieces

How detergent Works: • Detergent cleans dishes by removing fats & proteins. • Soap molecules & grease molecules made of two parts : Head (likes water) Tails (hates water) • When soap comes close to grease, it captures it, forming greasy soapy ball.

Release DNA from Wheat CELLS …. • The detergent removes the cell membranes and releases the DNA into the solution

Precipitate the DNA • Clouds of white strands are the DNA. • The DNA is not soluble in ethyl alcohol, so it precipitates out (becomes solid and drops out of the solution) where the 2 liquids meet. • Soap bubbles from the solutions will get trapped in the DNA strands.

COLLECT THE DNA • Observe the cloudy layer. This is the DNA. Place a clean glass stirring rod in the beaker with the DNA. • Collect the DNA by winding it on the rod, and turning the rod in one direction.

Wheat Germ DNA

Cheek Cell DNA or “Cheek to Cheek” or “See your DNA = Cheek the Code of Life”

“Spit Happens” DNA extraction of Cheek Cells Basic procedure: • Lyse the cells rupturing the cell membranes and nuclear membrane to release DNA • Use Gatorade: swish • Spit, spit

RELEASE DNA FROM THE CELLS • Add detergent to break open cell membrane to release DNA

Precipitate the DNA • Add ethyl alcohol to solution of “spit” • What happens at the interface between the ethyl alcohol and the "DNA/spit" solution?

• DNA floats to surface • (bubbles with tiny hair like white strings)

COLLECT THE DNA • DNA is collected by winding it on the wooden stick or piece of spaghetti, and turning the rod in one direction.

What do you think he sees? • DNA on slide • Use cover slip. • Use diaphragm: to adjust the amount of light

Why use Enzymes in some DNA EXTRACTIONS? • Enzymes speed up chemical reactions. • Meat Tenderizer has the enzyme PAPAIN. • Used to cut proteins away from the DNA. • Also, helps break down DNAase (enzyme that breaks down DNA)

Why is it important to isolate the DNA of any organism? • Biodiversity • Medical cures • Medical advancement • • Organisms live in different environments Survival of endangered species(reproduction) Blending of DNA (plants. . genetic engineering) Making Healthy Smoothies.