A unique collection of step-by-step methods for the characterization, purification, and expression of mammalian lipases and phospholipases. The methods include the preparation of a variety of unique substrates for the determination of lipolytic activity, the isolation of purified lipase preparations, and the development of high expressing recombinant systems. There are also methods for the immunodectection and production of immunological reagents and the analysis of biochemical properties, such as subunit size, lipase kinetics, enzyme immobilization, and ligand interactions. The protocols covers more than a dozen specific enzymes, and provide well-established methods that can be adapted to the discovery of new lipase enzymes.