DNA extraction is used in diagnostic processes, detecting viruses and police forensics. Being able to pull or extract the DNA from the rest of a cell or a sample gives scientist the clearest look at the samples they have and allows them to identify the individual pieces of the DNA.
Being able to identify these tiny pieces of DNA means that scientists can match them against other samples to identify a person or even create vaccines against a disease. DNA is extracted by breaking open a cell and then degrading the proteins. The sample is then put in a centrifuge which separates the parts of the broken open cell, which scientists can then extract for sequencing or other methods of testing.