When first conceived, t only was the aim of Protocols for Oligo- nucleotides and Analogs to provide wide coverage of the ohgonuc- otide chemistry field for readers who are well versed within the field, but also to give investigators just entering into the field a new perspective. The very first book on this topic was edited and published by Michael Gait in 1984, in whose laboratory I encountered the newer aspects of oligonucleotide chemistry. Since then, oligonucleotide research has developed to such an extent that its uses extend far beyond basic studies, and w find wide application throughout clinical science as well. Until recently, the major application of oligonucleotides has been in the area of DNA-based diagstic and antisense oligonucleotid- based therapeutic approaches. However, oligonucleotides are w also being used as therapeutic agents and are thus frequently found in clinical trials in humans. Synthesis of unmodified oligonucleotides using automated synthe- sizers has become a common practice in numerous laboratories. How- ever, improvements on the existing techniques and the introduction of ever newer methods for oligonucleotide synthesis is constantly driving ahead in the leading research laboratories. And several new oligonucle- otide analogs have been synthesized and studied for their individual prop- erties in recent years. The present volume strives to bring the readers the most up-to-date information on the newest aspects of synthesis of oligo- nucleotides and their analogs. A separate volume covers synthesis of oligonucleotide conjugates, along with most of the analytical techniques presently used for analysis of oligonucleotides.