Microfluidic systems have been shown to have great potential in a diverse array of biological applications including biomolecular separations, enzymatic assays, immunhybridization reactions, and the polymerase chain reaction. The use of nanoliter reaction volumes and parallel sample processing are potential advantages of microfluidic devices, making them ideally suited to chemical analysis, high-throughput screening applications, and other cases where reagents are limited. The goal of this book is to detail some of the most recent advances in the biological applications of microfluidics given its now widespread utilization in many fields of science.