RNA Mapping

In the last years, an enormous progress has been made in the identifi cation of genomic sequences. Given that genomic sequences can have various functions (e.g., structural organization, gene regulation, transcriptional start, and protein coding), molecular characterization is essential for progressing from the initial identifi cation of genomic sequences to the delineation of a specifi c biological mechanism. Mapping of transcribed sequences is the initial step in functional characterization of genomic sequences. Northern blot analysis allows for a direct and detailed characterization of transcribed sequences, like size and splicing variants, and provides a relative comparison of transcript abundance between different cellular conditions. This method includes separation of total cellular RNA by size via gel electrophoresis, RNA transfer to a membrane, and RNA hybridization with a complementary labeled genomic probe.