I have a website for you to read into that will explain it further.
DNA extraction allows scientists to get DNA out of its usual habitat and state (contained within cells and associated with proteins). You can’t do much with it when it’s all tangled up with proteins and surrounded by other cellular structures, so extraction is necessary to do further testing.
How is DNA extraction useful for scientists? - Quora
www.quora.com/How-is-DNA-extraction-useful-for-scientists