(d) dna extraction practical

What are the steps of extraction

Grind sample with mortar and pestle - breaks down cell walls

Add detergent - dissolves plasma membrane

Add protease enzyme usually pineapple juice to break down histone

Filter to remove solids

Add salt to clump dna together

Pour cold alcohol on top

Why do we use detergent

It dissolves fatty membranes cux it has polar and non polar sides allows them to dissolve and disrupt the bilayer

Why is alcohol used

DNA is insoluble in alcohol so should precipate the dna out the solution

What will dna be seen as

White strands

Can be picked up by spooling it onto a glass rod