Hydrazinolysis is a versatile method to liberate N-linked glycans from glycoproteins. However, the method is usually performed with anhydrous hydrazine, a highly toxic and explosive chemical used in rocket fuel. Thus despite the need to produce functionally important glyco-materials, hydrazinolysis is limited to small scale (e.g., 0.2-1 mL) reactions. In the present study, we report an alternative procedure for hydrazinolysis using hydrazine monohydrate in place of anhydrous hydrazine. The developed procedure was applied to both purified glycoproteins (Taka-amylase and transfierrin) and hen egg yolk protein fraction with comparable yields to the traditional method using anhydrous hydrazine. The sialyl linkage of alpha 2-6disialobiantennary oligosaccharides proved to be fully stable. The developed procedure facilitated the large-scale preparation of N-linked glycans. The new method should make a substantial contribution to both small and large-scale production of functional glycans, including therapeutically relevant human-type glycans. (c) 2007 Elsevier Inc. All rights reserved.