The development of techniques and methods for protein purification has been anessential pre-requisite for many of the advancements made in biotechnology. This handbook provides advice and examples for a smooth path to protein purification. Protein purification varies from simple one-step precipitation procedures to large scale validated production processes. Often more than onepurification step is necessary to reach the desired purity. The key to successful andefficient protein purification is to select the most appropriate techniques, optimise their performance to suit the requirements and combine them in a logicalway to maximise yield and minimise the number of steps required. Most purification schemes involve some form of chromatography. As a resultchromatography has become an essential tool in every laboratory where proteinpurification is needed. Different chromatography techniques with different selecti-vities can form powerful combinations for the purification of any biomolecule.The development of recombinant DNA techniques has revolutionised the produc-tion of proteins in large quantities. Recombinant proteins are often produced informs which facilitate their subsequent chromatographic purification. However,this has not removed all challenges. Host contaminants are still present and pro-blems related to solubility, structural integrity and biological activity can stillexist.Although there may appear to be a great number of parameters to consider, witha few simple guidelines and application of the Three Phase Purification Strategythe process can be planned and performed simply and easily, with only a basic knowledge of the details of chromatography techniques.