Purification of DNA from strawberries Flashcards
surfactants
dissolve lipid components of cell membranes, exposing the proteins and nucleic acids within the cell.
counter ion
the ion that accompanies an ionic species in order to maintain electric neutrality- allows DNA to precipitate
precipitate
makes visible from a solution.
DNA extraction
- Detergent and salt in beaker
- Strawberries and distilled water blended
- Add deionized water (purified) to the salt and detergent mixture. Dissolve by stirring slowly. Avoid foaming, do not shake.
- Add strawberry to mixture. Mix solution slowly for 5 minutes.
- Filter through coffee filter in new beaker. Let drain for several minutes.
- Pour filtered solution slowly into a beaker of VERY cold ethanol.
- Sit for 5 minutes on ice.
- Slowly twirl dowel at the alcohol interface in test tube. Pull DNA strands out of test tube- spooling the DNA.
Laundry detergents
Dissolves lipid components
Salt
Na+ is the opposite charge of DNA which neutralizes the charge
Alcohol
Alcohol is nonpolar and neutralized the phosphate in DNA
What allows the DNA to precipitate?
The salt and alcohol solution. The salt acts as a counter ion and the alcohol neutralizes the phosphate.
DNA chemical properties
-Phosphate: negative charge
homogenization
Strawberry sample blended up together to separate the cells from each other. This makes the cell ingredients more accessible to the reagents that follow
lysis and digestion
detergent and salt added to lyse the cell membrane and free the DNA. DNA is surrounded by proteins and other cell components.
Separation
DNA is separated from the rest of the cell contents by adding cold, pure, ethyl or isopropyl alcohol. DNA is not soluble in these alcohols so it will condense to try to minimize its contact with the alcohol
