Nucleic acid detection technologies - Labels, strategies, and formats

Currently, no consensus exists on assay formats, labels, or detection react ions for nucleic acid assays. New labels continue to be developed and teste d, and recent candidates include acetate kinase, firefly luciferase, and ge nes for enzymes. An additional trend is toward nonamplification strategies (e.g., branched chain and dendrimer type assays) as alternatives to the pop ular PCR and related amplification strategies. The new wave of microanalyti cal devices (microchips, with nanoliter to microliter internal volumes), ma ssively parallel simultaneous test arrays, and the desire to produce hand-h eld sensors present new challenges and requirements for nucleic acid detect ion methods (e.g., analysis of large arrays of micrometer-sized spots of nu cleic acid with high resolution). Here I review selected developments and n ew directions in nucleic acid assays. (C) 1999 American Association for Cli nical Chemistry.