This practical laboratory manual provides an essential source of reference, information and guidance for all laboratory and clinical immunologists. It fully describes the methods used in diagnostic immunopathology, and discusses the interpretation and value of the parameters measured. It also answers important practical questions: which parameters are useful in arriving at a diagnosis; which are useful for monitoring the severity of a disease; what level of precision is achievable, and what level is useful; how do we measure accuracy, and how do we achieve inter-laboratory consistency? Each chapter has a brief introduction which provides some general comments on the procedures involved. The methods section contains detailed descriptions with helpful notes on the advantages and disadvantages of different methods and potential pitfalls. Finally, each chapter concludes with a section on clinical applications, which discusses the interpretation, value and limitations of the information obtained, and asks what alternative interpretations should be considered, and what additional information is called for.