The subcellular localization of mRNA, and small RNA movement and trafficking of these molecules in an organism are important components of cellular and organismal regulation and communication. The next frontier for analysis of RNA will involve analysis at a single-molecule level, and at the subcellular level. This invention relates to methods and materials for sensitive detection of target molecules, particularly to methods and materials for binding or otherwise associating with target molecules and producing a signal for detection of, for example, spatial and/or temporal localization, and more particularly to methods and materials for the above using aptamers which bind to a chromophore or otherwise produce fluorescence or other detectable signal. This invention further relates to aptamers which bind to chromophores such as, for example, biliverdin or other related molecules, and also to such molecules which exhibit fluorescence or other detectable signals.
