Nucleic Acids Hybridization: Potentials and Limitations -- Selective Suppression of Polymerase Chain Reaction and Its Most Popular Applications -- Suppression Subtractive Hybridization -- Stem-Loop Oligonucleotides as Hybridization Probes and Their Practical Use in Molecular Biology and Biomedicine -- Normalization of cDNA Libraries -- Primer Extension Enrichment Reaction (PEER) and Other Methods for Difference Screening -- Subtractive Hybridization with Covalently Modified Oligonucleotides -- Coincidence Cloning: Robust Technique for Isolation of Common Sequences -- DNA Hybridization in Solution for Mutation Detection -- Current Attempts to Improve the Specificity of Nucleic Acids Hybridization -- Concepts on Microarray Design for Genome and Transcriptome Analyses. Watson-Crick hybridization of complementary sequences in nucleic acids is one of the most important fundamental processes necessary for molecular recog- tion in vivo, as well as for nucleic acid identification and isolation in vitro. This book is devoted to a large family of in vitro DNA hybridization-based expe- mental techniques. A wide spectrum of experimental tasks covered by these approaches includes finding differential sequences in both genomic DNAs and mRNAs, genome walking, multiplex PCR, cDNA library construction starting from minute amount of total RNA, rapid amplification of cDNA 5?- and - ends, effective smoothing of the concentrations of rare and abundant transcripts in cDNA libraries, recovery of promoter active repeats and differentially met- lated genomic DNA, identification of common sequences in genomic or cDNA sources, new gene mapping, finding evolutionary conserved DNA and both s- gle-nucleotide and extended mutation discovery, or large-scale monitoring. Several approaches, such as microarray hybridization, have become extremely popular tools for specialists in biochemistry and biomedicine, whereas the pot- tial of many other advantageous techniques seems to be underestimated now. Analysis of differential gene expression requires application of global approaches that represent a leading tool in postgenomic studies and include transcriptome and proteome analysis, as well as methods allowing populati- wide sequence and functional polymorphism analysis. Central to these new technologies are DNA chips designed for quantitative and qualitative uses.