Reactive oxygen species (ROS) are a type of hydroxyl ions that are generated during normal metabolism in all cells of the body. Naturally occurring ROS are not known to cause damage at these normal, regulated levels. However, oxidative stress (OS) refers to the overproduction of ROS and can lead to DNA damage, mutation, and disease. Bioflavonoids are compounds found in soy, fruits, vegetables and when part of a normal diet, they have antioxidant properties and a range of desirable health benefits. However, they are also found in high amounts in over-the counter supplements and some energy drinks. My research is focused on the idea that high doses of bioflavonoids may cause the overproduction of ROS leading to OS and DNA damage in a dose-dependent manner. The increased production of ROS can be easily tracked in cells using a dye called Dihydroethidium (DHE). Once oxidized, DHE binds to DNA in cells and emits a red fluorescence that can be easily seen using a fluorescent microscope or by a special detector called flow cytometry. By treating cells with different bioflavonoids and at a range of doses, I will determine which ones cause OS and may be harmful to human health when ingested in large quantities.