Trehalose, Lyophilization Certified, is an effective lyoprotectant which maintains the conformation of proteins and other biomolecules during the removal of water during freeze drying.  This non-anomeric disaccharide (two glucose monomers linked via their anomeric carbons) provides the same type of protection as sucrose, though trehalose is less likely to cause sample collapse.  Each lot is tested to ensure that it is effective a preserving protein structure and activity.