The practical problems encountered when purifying and visualizing small amounts of antigens from complex cellular and protein mixtures are explored. Practical aspects and the relative advantages and disadvantages of immunoprecipitation and blotting, the two most commonly used antibody techniques, are discussed. As glycosylation of antigens is becoming recognized as an important factor in the progress of many diseases, a short section on the use of lectins in precipitation and blotting techniques is also included. It is highly likely that a combination of precipitation followed by blotting, using either lectin followed by antibodies or antibody followed by lectins, will become a valuable tool in characterizing cellular antigens and the progression of disease.