The transfer of scientific material and data, which are scientific inputs, is fundamental to knowledge creation dynamics. This transfer is being controlled, more and more, by the use of Material Transfer Agreements (MTAs). Therefore, the effect of MTAs on the dynamic of knowledge creation is an important concern. The aim of this research is to characterise the restrictions imposed by MTAs, and their determinants. We consider MTA diversity based on a comprehensive analysis of the clauses included in 171 MTAs signed by two French universities. We show that the clauses included in MTAs depend on several factors such as kind of material involved, research field, patenting and collection of material. We find that the presence of an industry actor is not associated to more restrictions on publication and intellectual property. We propose a typology of MTAs corresponding to different transfer situations. We discuss the role of MTAs as collaborative tools and the influence of the legal, scientific, political and organisational context.