The technology developed as part of the Human Genome Project made sequencing a routine method in the clinical laboratory. Small, cost-effective sequencers are available for rapid sequencing. In the clinical laboratory, sequencing is actually resequencing, or repeated analysis of the same sequence region, to detect mutations or to type microorganisms, making the task even more routine. The technology continued to develop, reducing the cost and labor of sequencing to detect multicomponent diseases or to predict predisposition to disease. Massive parallel or next-generation sequencing has supplemented and/or replaced Sanger sequencing in many clinical laboratories, and even this technology has evolved into lower-cost, user-friendly protocols. Accurate and comprehensive sequence analysis is one of the most promising areas of molecular diagnostics.