This application note evaluates sterile and contamination-free lyophilization using the BÜCHI Lyovapor™ L-210 Pro, Frontloader and a Teclen Bag with a hydrophobic membrane. The membrane acts as a sterile barrier and prevents product fly-out without affecting sublimation or drying time. Comparable residual moisture levels were achieved with and without the bag, demonstrating its suitability for protecting sensitive samples during freeze-drying.