Drosophila Melanogaster has been extensively used as a model system to study ionizing radiation and chemical induced mutagenesis, double strand break repair and recombination. However, there are only limited studies on nucleotide excision repair in this important model organism. In this study, we immunopreciptated DNA-directed RNA polymerase II (RPII215) complex from untreated and UV iradiated drosophila S2 cells and identified the protein that interact with it by mass spectrometry.