Quantitative analysis is a key aspect of any researcher's life in molecular biology. This book is a hands-on guide to quantitative analysis in biological experiments. The material is primarily aimed at working molecular biologists, but the scope and clarity of presentation make it equally suitable as an introduction for students. The topics covered range from the basics - such as measuring the concentrations of macromolecules - through considerations of binding constants and the kinetics of molecular interactions, and ends with a consideration of data analysis.