Non-radioactive labelling and detection of nucleic acid probes

Abstract

Abstract Non-radioactive indicator systems are based on the detection of various biological target molecules (analytes) by selective interaction with specific binding partners (probes). Appropriate detector systems are coupled to these probes, either directly by covalent binding or indirectly by additional specific high-affinity interaction. Most of the recently developed non-radioactive systems are based on the enzymatic, photochemical, or chemical incorporation of a reporter group (1, 2) which can be detected with high sensitivity by optical, luminescence, fluorescence, or metal-precipitating detection systems (3-5). Electrochemical detection systems using pH electrodes or sensor technology have also been described (6, 7). In addition, attempts are being made to use specific labelling and detection systems not only for the detection of different target molecule specificities, but also for the detection of a large variety of different kinds of biomolecules such as proteins or glycans (universal detection systems). The various non-radioactive systems can be classified as direct or indirect. These assays differ in the number of components and thus the number of reaction steps used for the detection reaction. Whereas direct systems are mostly used for the detection of standardized target biomolecules, the more flexible indirect systems are often applied to detect different target bio molecules of variable specificity.