With the increasing use of mammalian cells in research and in the clinic, there is a critical need for effective methods to protect these cells during manipulation or long-term storage. The Paulick lab has developed a protection method that exploits trehalose, a naturally-occurring disaccharide. Trehalose serves as a cellular protectant for many types of organisms when they are subjected to stressful conditions like cold temperatures and dehydration. While trehalose cannot readily cross the mammalian cell membrane, modified trehalose analogues, in which the hydroxyl groups have been converted into hydrophobic esters, can passively diffuse through the membrane. Once inside the cell, the ester groups are enzymatically cleaved to generate free trehalose. Previous work from our lab has demonstrated that esterified trehalose analogues successfully deliver free trehalose into mammalian cells and, most importantly, provide protection to these cells from heat shock. This research focuses on the use of the butyrylated trehalose analogue, Bu4Tre, for the protection of mammalian cells. I will discuss the synthesis of Bu4Tre, as well as its ability to deliver free trehalose into mammalian cells and act as a cellular protectant. Modified trehalose analogues, including this butyrylated analogue, offer scientists a facile means to deliver high concentrations of trehalose into mammalian cells for use as a cellular protectant.