S-1 Quantification of prospective type 2 diabetes mellitus biomarkers by stable isotope dilution with bi-labeled standard glycated peptides Alena Soboleva, 1,2† Maciej Modzel, 3† Anna Didio, 1,2 Halina Płóciennik, 3 Monika Kijewska, 3 Tatiana Grischina, 1 Tatiana Karonova, 4,5 Tatiana Bilova, 6 Vasily Stefanov, 1 Piotr Stefanowicz, 3 Andrej Frolov 2* Supplementary Information 1 Department of Biochemistry, St. Petersburg State University; 2 Department of Bioorganic Chemistry, Leibniz Institute of Plant Biochemistry; 3 Faculty of Chemistry, University of Wroclaw; 4 Federal Almazov North-West Medical Research Centre; 5 The First Pavlov St. Petersburg State Medical University; 6 Department of Plant Physiology and Biochemistry, St. Petersburg State University † These authors contributed equally to the manuscript *Corresponding author: Dr. Andrej Frolov Leibniz Institute of Plant Biochemistry Department of Bioorganic Chemistry Weinberg 3, 06120, Halle/Saale, Germany Tel. +49 (0) 345 55821350 Fax. +49 (0) 345 55821309 Email: afrolov@ipb-halle.de Electronic Supplementary Material (ESI) for Analytical Methods. This journal is © The Royal Society of Chemistry 2016