In this scenario, an investigator added substance X to a dish containing culture of cells, then he found out that highly concentrated mitochondria was present in the dish through the help of fluoresces under the right sort of light. It can be describe then that substance X has absorbed light or it has electromagnetic radiation. Therefore, the investigator can make an assumption that substance X might be used to identify mitochondria in living cells for its unique characteristics in which it glows when exposed to ultraviolet light.