What is the basic principle behind DNA microarrays?
DNA microarray performance depends on Watson-Crick base pairing between immobilized probes and fluorescently labeled target nucleic acids. Under controlled temperature and salt concentration, complementary sequences form stable duplexes, while mismatched sequences are removed during stringent washes. The resulting hybridization signal strength reflects thermodynamic stability and target concentration, permitting quantitative comparison across samples. PCR amplification, competitive binding unrelated to nucleic acid complementarity, and northern transfer principles describe separate techniques.
Ref: NCERT Biology Class XII Principles on Klenow fill-in labeling, Lehninger Chapter 9 DNA cloning techniques, and Molecular Cloning by Sambrook Chapter 10 documenting end-labeling of cohesive termini.
