Using surface-enhanced Raman scattering (SERS) and fluorescence spectroscopy for screening yeast extracts, a complex component of cell culture media

Yeastolate or yeast extract, which are hydrolysates produced by autolysis of yeast, are often employed as a raw material in the media used for industrial mammalian cell culture. The source and quality of yeastolate can significantly affect cell growth and production; however, analysis of these complex biologically derived materials is not straightforward. The best current method, liquid chromatographymass spectrometry (LC-MS), is time-consuming and requires extensive expertise. This study describes the use of surface-enhanced Raman scattering (SERS) and fluorescence excitationemission matrix (EEM) spectroscopy coupled with robust principal component analysis (ROBPCA) for the rapid and facile characterization and discrimination of yeast extracts in aqueous solution. SERS using silver colloids generates time-dependent signals, where adenine is the strongest contributor, and the spectra are stable and reproducible (