There has been a convergence of progress in chemistry and biology. Among the important advances resulting from this convergence is the development of methods for generating molecular diversity and for detecting and quantifying small quantities of biological or chemical material. This advance been facilitated by fundamental developments in chemistry, including the development of highly sensitive analytical methods, solid state chemical synthesis, and sensitive and specific biological assay systems.
Analyses of biological interactions and chemical reactions, however, require the use of labels or tags to track and identify the results of such analyses. Typically biological reactions are monitored by radiolabels or direct or indirect enzyme labels. Chemical reactions are also monitored by direct or indirect means, such by linking the reactions to a second reaction in which a colored, fluorescent, chemiluminescent or other such product results. These analytical methods, however, are often time consuming and tedious. There is, thus, a need to develop alternative methods for tracking and identifying analytes in biological interactions and the reactants and products of chemical reactions.