Biological processes can be traced through study of gene-expression via a molecular beacon (singlestranded DNA, ssDNA), a hairpinshaped oligonucleotide with a fluorophore (donor) and a quencher (acceptor). The hairpins stem has two ends of complementary DNA (cDNA) that pair up. When hybridized, the fluorophore and quencher are close, producing little or no fluorescence. Molecular beacons are used to study enzyme interactions, cDNA sequencing, and biosensing.1 模塊式熒光光譜儀-Fluorolog-3 高靈敏一體式熒光光譜儀-FluoroMax-4