Nucleic Acid Detection Technologies--Labels, Strategies, And Formats‪.‬

The range and scope of nucleic acid-based assays continues to expand (e.g., medical, forensic, and environmental applications) (1-3). Many of the types of nucleic acid assays developed require a secondary detection technology, e.g., a label, because a nucleic acid does not have intrinsic properties that are useful for direct high-sensitivity detection. As yet there is no consensus on the choice of a label for nucleic acid detection, and none of the current labels has the attributes of a universal or ideal label. Key factors governing label choice include stability, sensitivity of detection, speed and convenience of detection, and the overall cost for the label, detection reagents, and detection system. In addition, modulation of a property of a label when a conjugate binds to a binding molecule is also desirable because it can form the basis of nonseparation assays. Two new analytical formats, the microchip and the microarray, pose new challenges for nucleic acid detection (4-6). Here I review current directions in nucleic acid analysis and discusses recent strategies for ultrasensitive detection (Table 1). Labels and Sensitivity