In this updated second edition, leading researchers apply molecular diagnostics to the many recent advances that have occurred in polymerase chain reaction( PCR)-based technologies. Highlights include real-time PCR, which allows the technique to be performed in a quantitative manner with improved sensitivity, robustness, and resilience to carryover contamination, mass spectrometric analysis of nucleic acids, and circulating cell-free nucleic acids in plasma. The authors apply these innovations to a broad spectrum of applications, including gene expression, methylation, trace molecule, gene dosage, and single cell analysis.