First the target DNA is selected. While selecting the desired DNA, one should keep in mind that it should be healthy, strong, disease free and of superior breed. Selected cells are first lysed slightly. Cell membranes are broken down using enzymes like lysozyme (bacterial cells), chitinase (fungal cells), cellulase (plant cells). The lysed cells are then centrifuged into test tubes. A quantity of cesium chloride solution is introduced into a centrifuge test tube. The solution is then centrifuged. As a result, a band of DNA is formed on the test tube. DNA is mixed with other components to form a homogenate. DNA is separated from the homogenate using enzymes such as protease (protein), ribonuclease (RNA), amylase (sugar), lipase (fat). The purified DNA is then precipitated as a thread by immersion in a cold ethanol solution. The desired DNA is selected from the degraded DNA.