Detergent/Enzyme/Heat

•Break down the cell wall•60o C breaks down nuclear

membrane, but not DNA; 80o C will break down DNA as well

Chemistry of DNA extraction - some bio too!

DNA Extraction from DNA Extraction from Green Split Peas or raw Green Split Peas or raw wheat germwheat germ! !

DNA Extraction Procedure - 1• Blend for 15 seconds:» DNA source – 100 ml green split

peas» Cold water – 200 ml» Large pinch of table salt

• Pour mixture through a • strainer• Add detergent – 2 tablespoons• Let sit for 5 – 10 minutes

DNA Extraction Procedure - 2• Pour mixture into test tubes

– 1/3 full• Add meat tenderizer – dip

of wet stick• Tilt test tube• Slowly pour rubbing alcohol

into the tube• Equal amounts of alcohol &

DNA mixture• Watch DNA appear in the

alcohol

SoapGrease Grease and Soap

Heads

Tails

DNA appears at alcohol/ mixture interface and can be spooled onto a stirring rod

Salt• (Na +) is attracted to the phosphate

group• Denatures the protein that lyses

(breaks down) DNA

Alcohol

Cold for two reasons:

•Slows down enzymes that break up DNA

•DNA is less soluble in cold temperatures

R-OH

• Water is HOH, like dissolves like• Alcohol dissolves the water and

pulls it away from the DNA • R is shorthand for any organic

group or hydrocarbon