Storage and Lyophilization of Pure Proteins

This article outlines empirical procedures for the storage of pure proteins with preservation of high levels of biological activity. It describes simple and workable means of preventing microbial contamination and proteolytic degradation, and the use of various types of stabilizing additives. It sets out the principles of lyophilization (otherwise known as freeze-drying, a complex process comprising freezing, primary dying, and secondary drying stages). There follows a general procedure for the use of lyophilizer apparatus with emphasis on best practice and on pitfalls to avoid. The use of modulated differential scanning calorimetry to measure the glass transition temperature, a key parameter in the design and successful operation of lyophilization processes, is described.