MODEL RELEASED. DNA extraction experiment. Teenage boy using a stopwatch on a mobile phone during a home experiment to extract DNA (deoxyribonucleic acid), in this case from a banana. The banana is cut up and mashed, and then placed in a beaker with warm water added. Washing detergent is added to break the cell membranes. The mixture is kept warm for 12 minutes, then placed in an ice bath for 5 minutes. After filtering (shown here in instructions), the liquid is pipetted into a test tube and salt and chilled isopropyl alcohol added. This precipitates the DNA. More chilling in ice (10 minutes) produces a visible mass of stringy DNA.