Creation and filtering of a recurrent spectral library of CHO cell metabolites and media components

Abstract

This paper reports the first implementation of a new type of mass spectral library for the analysis of Chinese hamster ovary (CHO) cell metabolites that allows users to quickly identify most compounds in any complex metabolite sample. We also describe an annotation methodology developed to filter out artifacts and low‐quality spectra from recurrent unidentified spectra of metabolites. CHO cells are commonly used to produce biological therapeutics. Metabolic profiles of CHO cells and media can be used to monitor process variability and look for markers that discriminate between batches of product. We have created a comprehensive library of both identified and unidentified metabolites derived from CHO cells that can be used in conjunction with tandem mass spectrometry to identify metabolites. In addition, we present a workflow that can be used for assigning confidence to a NIST MS/MS Library search match based on prior probability of general utility. The goal of our work is to annotate and identify (when possible), all liquid chromatography‐mass spectrometry generated metabolite ions as well as create automatable library building and identification pipelines for use by others in the field.

Precision fermentation with mass spectrometry‐based spent media analysis

“…This is followed by creating a list of identified metabolites for targeted analysis and quantification. Recently, Telu et al reported the creation of a spectral library for cellular and media metabolites in CHO cell cultures using a hybrid search of the NIST17 (National Institute of Standards and Technology) library (Telu et al, 2021). However, for accurate quantification, internal standards (IS) are used and normalization of all metabolite concentrations with the IS concentration is needed.…”