ABSTRACT
The identification of the DNA structure as a double-stranded helix consisting of two nucleotide chain molecules was a milestone in modern molecular biology. Most of the methods for DNA characterization are based on its ability to form fully or partially complementary double helices from two complementary single strands. To detect hybridization events, one strand (target) is usually immobilized on a solid support (e.g., nylon membranes or glass slides), whereas its counterpart (probe) is present in the hybridization solution. The probe is labeled and hybridization events are thereby detected on the solid support at the position of the immobilized target. Hybridization with different known probes can be used to characterize unknown targets, such as is used in oligonucleotide fingerprinting. The reverse situation — the target DNA is known and the hybridization solution is not defined — is encountered when DNA chips or microarrays are used to monitor gene expression.
