A c c e p te d P r e p r i n t 1 Systems Biotechnology Biotechnology and Bioengineering DOI 10.1002/bit.24983 Metabolic signatures of GS-CHO cell clones associated with butyrate treatment and culture phase transition † Nuno Carinhas 1,2,* , Tiago M. Duarte 1,2,* , Laura C. Barreiro 1,2 , Manuel J. T. Carrondo 1,2,3 , Paula M. Alves 1,2 , Ana P. Teixeira 1,2 1 iBET, Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901 Oeiras, Portugal. 2 Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal 3 Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal. * These authors contributed equally to this work. Correspondence to: A. P. Teixeira anat@itqb.unl.pt Keywords: GS-CHO cell clones, butyrate treatment, 1 H-NMR, exometabolomics, metabolic flux analysis, specific productivity † This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as doi: [10.1002/bit.24983] Additional Supporting Information may be found in the online version of this article. © 2013 Wiley Periodicals, Inc. Received March 20, 2013; Revision Received May 26, 2013; Accepted June 12, 2013