1. Lab 5
DNA Extraction

2. (1) DNA Extraction from Plant Cells
Objective:
Isolating DNA from plant cells and visualizing it directly .
To extract DNA from plant cells like strawberry, banana and peas,
1-we need to (destroy cell wall and cell membrane)
2-we need to separate DNA from other cell components like proteins, carbohydrates and lipids through precipitation.
3-we can collect DNA molecules by cold alcohol and DNA can be seen directly.
Strawberry character :
1- Is octoploid, meaning that it has 8 copies of each chromosome, so it has a large amount of nucleic acid.
2- Fresh fruit contains pectinase and cellulase enzymes that helps lysing cell wall.

3. Cell organelles and other components can be separated from each other by :
centrifugation :
1-depending on their physical properties as: size and density.
2-This can be done by using different speeds at different periods of time.
3-Centrifugation speed is measured by revolutions per minute (rpm).
4-Bigger and heavier components precipitate at the bottom and called pellet,
5-smaller lighter substances float upper and called supernatant.
Materials : (Strawberry or banana or green peas)- Ice ethanol alcohol 99%- Buffer (90ml water +10 ml detergent +small amount of NaCl)- large tube- glass rod.

4. Steps:
1- Put fruit in mortar or inside plastic bag, then mash manually till it becomes creamy.
2- Add 10 ml of buffer.
3- Leave for 2 min.
4- Filtrate the mixture with piece of Gauze in glass cone.
5- Discard the precipitant in the Gauze. And put the liquid filtrate in large tube.
6- Put the glass rod in ice to become iced , then put it in the large tube.
7- Pour ice ethanol alcohol on the glass rod (inside tube)
8- Observe fibers of DNA stuck on the glass rod.
Observation: DNA molecules appears as colorless gelatinous substance sticking to the glass rod.