日本質量分析学会 第66回質量分析総合討論会

Program

Poster Presentations

Day 3, May 17(Thu.)  Poster

Development of interference spectra removal method to increase quantification accuracy

(1Kyoto Univ., 2Kyoto Univ.)
oMio Iwasaki1, Tsuyoshi Tabata1,2, Yuka Kawahara1, Yasushi Ishihama2, Masato Nakagawa1

Quantification accuracy is an important problem to do differential gene expression analyses. Isobaric tags for relative and absolute quantification (iTRAQ) method is widely used tool to obtain quantification data among different cell types. Although, quantification accuracy and precision of iTRAQ is quite high, it has been known that its quantification accuracy is greatly decreased and exhibit lower quantification differences among cell types in the presence of interference (co-eluted other kinds of peptides). Here, we developed a new algorism to obtain higher quantification accuracy by removing interference spectra using the information of surrounding MS/MS acquisition.
To know the impact on quantification efficiency in the presence of interference problem, we used iTRAQ labelled E.coli cell lysate (four plex) as a theoretical quantification model and HeLa cell lysate as an interference model. Without interference, the observed ratios of each E .coli iTRAQ combination were appropriate to theoretical value irrespective of the usage of our method. With interference, the observed ratio was deviated from the theoretical value, but the ratio was 1.25-fold increased using our method. From the result, at least 60% of the obtained spectra were co-eluted with other kinds of peptides. This method might be useful for all iTRAQ users who want to increase quantification efficiency.