This updated volume provides stepwise instructions for the analysis of numerous clinically important analytes by mass spectrometry. Mass spectrometry offers clinical laboratory scientists a number of advantages including increased sensitivity and specificity, multiple component analysis, and limited need for specialized reagents. These techniques are essential in laboratory fields including endocrinology, biochemical genetics, drug analysis, proteomics, and pathogen identification. Written in the highly successful Methods in Molecular Biology series format, chapters include introductions to their respective topics, lists of the necessary materials and reagents, step-by-step, readily reproducible laboratory protocols, and tips on troubleshooting and avoiding known pitfalls.