The ease of extraction and clear visibility of strawberry DNA makes the strawberry DNA extraction lab popular in Biology courses. The lab involves using common household items, such as detergent, rubbing alcohol and salt, to remove the DNA from the nucleus of strawberry cells. Once removed, the DNA clumps and is precipitated out of the solution, making it visible to the naked eye.
To begin the strawberry DNA extraction lab, a mixture of detergent, salt and water is prepared. This mixture is added to smashed strawberries, and is then filtered through cheesecloth to remove the pulp. The detergent mixture dissolves the nuclear membrane that contains the cell's DNA, allowing the DNA to clump and extract from the cell. Rubbing alcohol is slowly added to form a layer on top of the strawberry juice. The rubbing alcohol causes the extracted DNA to precipitate out of the mixture. The lab participant can then remove the DNA from the container for examination by twisting it around a stirring rod.
Strawberries are often used for DNA extraction exercises because they contain a lot of DNA per cell. DNA contains the instructions for everything that happens inside a cell, serving as a blueprint for building and maintaining an organism's structure.