A schematic diagram of the MultiCode system is shown in Fig. 3 . The MultiCode process has three steps. For the first step, regions of the target of interest are amplified by PCR using primers that contain a single 5Ј-iC. In the second step, the amplicons from the first step are used as templates for the TSEs, and iC directs specific diGTP-biotin incorporation. The TSEs are coded on their 5Ј ends with sequences that specifically recognized short complementary sequences (EraCodes) attached to an addressed solid matrix. The molecular recognition of any given code with its EraCode is specific enough so that increased temperatures, incubation steps, or washings are not required (typical requirements for hybridization capture using only naturally occurring base chemistries). During this second step, labels are placed site specifically on the TSEs. This process requires the presence of iC-containing amplicons that are complementary to the TSE. When the correct target is available, the extension reaction continues to the 5Ј end of the amplicon, where the diGTP-biotin is used to insert the biotin into the TSE. Specificity and signal consistency arise when coded TSEs are covalently attached to a single biotin reporter in the presence of the correct target. In the final step, the TSEs are captured on the solid matrix and detected. The presence of the target is then determined by where the reporters are located spatially on the liquid matrix (created by the differentially colored microspheres).