Effect of Varying Salt Concentrations on DNA Extraction from Strawberries and Bananas

Abstract

A variety of methods have been used for DNA extraction. This experiment aims to understand the effects of salt concentration of a solution with a mixture of salt, water, and dish detergent on DNA yield of fruits. Prior research shows that strawberries and bananas yield a greater amount of DNA than other fruits, which will provide a more accurate comparative analysis. 40 grams of bananas and strawberries were mixed with salt water at varying concentrations (0, 0.0208, 0.0417, 0.0625, 0.0833), dish soap, and rubbing alcohol to allow for the precipitation of DNA into a measurable form. The results demonstrated relative alignment with the given hypothesis, which is that the yield of extraction increases with salt concentration, which is due to the ability of salt to neutralize DNA’s negative charge, separate it from the cell, and dissociate it from the water. An unexpected outcome of this research was the unusually high DNA yield from the mixture with 0% salt concentration. Since this trial was conducted in New Delhi, India, while the other trials were conducted on the mainland USA, it is possible that geographical differences in the chemical makeup of water, rubbing alcohol, or dish detergent allowed for DNA precipitation without the use of salt. Future research should be conducted to understand how salt may be unnecessary in the process of DNA extraction.