Biolumiscence is the ability of some living beings to produce light thanks to chemical reactions in these organisms. The bioluminescence of fireflies has been used as an important tool (analytical techniques) within various studio fields. Luciferin (substrate for providing bioluminescence) is encoded by specific DNA sequences. Thanks to genetic engineering these sequences have been copied in such a way that they can be used in tissues for research purposes or for purposes such as cancer treatment. This article will talk about how light is formed from fireflies and how it is used in various applications.