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

“See your DNA = Cheek the Code of Life” 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 swish swish Spit, 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.