DNA extraction is the removal of DNA strands from an organic compound. For example, during a DNA test for paternity, the father and child’s DNA are extracted from cheek swabs of their skin cells. The extraction process involves swirling the saliva around in a tube in a way that breaks up the cells. Once the cells are broken up, the DNA can be pulled out. Of course, DNA is microscopic, so the DNA is placed in a machine that can read it.