Book excerpt: This book is intended to be a working guide to the operation of capillary electrophoresis (CE) instrumentation. Since CE is still a rap idly maturing technique, detailed validated protocols are not widely established. Therefore, extensive experimental procedures are not pro vided for individual analyses. The intention is to provide general guide lines on the principles and practice of CE and to give an overview of the specific technologies and important application areas. Part I provides operating instructions for standard commercially available instruments. Guidelines are included for activities such as changing capillaries, method development, quantitative procedures, optimization of precision and sensitivity, and the validation of meth ods, fraction collection, and troubleshooting, as well as a quick guide to running a separation. The application range of CE is possibly the most diverse of all analytical techniques and ranges from large, complex macromolecules, such as proteins and nucleic acids, to small solutes, such as organic drugs and inorganic anions and cations.