Presented are laboratory procedures of a serologic or immunologic nature for use in the diagnosis of a variety of infectious and noninfectious conditions. Included are tests for the detection of specific antibodies in the patient's serum, as well as immunologic tests for the detection of other products in the patient's serum and biological fluids. For the more frequently performed tests, the principle of the test, the reagents and the equipment needed, the preliminary steps, the complete test procedure, reporting results, and potential sources of error are presented. Additionally, the significance and interpretation of results of the tests are discussed in each chapter. (Author/CS)