Over the last decade, the applications of RNAi and microarray have increased exponentially, and are being applied to explore the expression profile of whole genome (particularly genes coding for proteins). Very little literature exists regarding RNAi against non-coding RNA (hot stuff nowadays) and the expression profile of non-coding RNAs. This book therefore, provide a systematic approach of targeting all types of non-coding RNAs (snoRNAs, snRNAs, SRP and Y RNA) by RNAi and expression profile of snoRNAs especially and all non-coding RNAs in general through micoarray after depletions of snoRNP component proteins by RNAi. All the work was carried out in model organism Canoehabditis elegans. These investigations should help shed some light on RNAi against non-coding RNAs and combinatorial effect of RNAi and microarray in examination of expression profile of snoRNAs and should be especially useful to scientists community working in the areas of RNAi, microarray and non- coding RNAs. This book could also be helpful for students and teachers in the subjects of Biology, Biochemistry, Biotechnology, Bioinformatics, Genomics and Microarray.