Dr. Stefan Zietze is Quality Control Manager at ProBioGen,Berlin, Germany. His responsibilities include the management of aQC-laboratory and the assistant director function for the QC/QAunit at ProBioGen. Stefan studied Pharmacy at theHumboldt-University in Berlin, Germany, where he received his M.Sc.in 2002. In 2003 he passed the examination as registeredpharmacist. From 2003 - 2006 he worked on his PhD-thesis with thetitle Evaluation, validation and application of an analyticalscheme for N-glycosylation analysis used for mammalian cellproduction processes as an external PhD-student in the QC/QA unitof ProBioGen, supervised by the Free University of Berlin. Besideshis expertise in the quality control of glycoproteins, he is alsoresponsible for transferring analytical methods, stability testingand formulation studies as well as the design of experiments bysophisticated statistical methods (DoE).