Ultra Violet Light Exposure Lab Report

Yeast Mutations due to Ultra-Violet Light Exposure
Summary:
Mutations have played one of the most important roles throughout life on Earth. Without genetic mutations there would not be the diversity of living species that we see today. Understanding how mutations work and how they are created is an important step in controlling and isolating genes for experimentation. In this experiment we tested the effects of Ultra-Violet light on growing single-celled yeast. We did this by first creating serial dilutions and growing our yeast colonies with no UV exposure. These yeast cells we used are a Trip1-289 mutant yeast strain and were grown on SC plates with tryptophan present. Next, we then grew two more sets of colonies exposed to UV light for pre-determined time intervals. One set was grown on SC plates while the other was grown on SD plates with no tryptophan present. The data suggests that yeast cells have a lower survival and have an increasing amount of mutations as they are exposed to UV light. Overall, this lab experiment helps to understand the basic concepts behind mutagenesis and the effects of UV light on growing cells.
Methods:
These yeast cells have the trip1-289 allele inactivated causing them to be unable to grow without the assistance of tryptophan. They were then plated into a SC and SD medium growth plates. The SC plate contained tryptophan and would allow yeast to grow freely while the SD plates contained no tryptophan. Then each plate was exposed to different intervals of UV exposure under the same bulb and allowed to grow. The colonies were then counted and graphed into Microsoft Excel.