Detection and Quantification of RNA Using Near-Infrared Northern Blot

Northern blot is a technique that enables the detection and quantification of RNA. In Northern blotting, RNA samples are size separated by gel electrophoresis, immobilized on a nylon membrane, and identified with a sequence-specific probe. Traditional Northern blots use radioactive ³²P-labeled RNA or DNA oligonucleotide probes to detect the RNAs of interest. Here we describe a nonradioactive Northern blot method using near-infrared (IR) fluorescent probes. Use of IR-fluorescent probes enables this "irNorthern" method to achieve similar sensitivity as traditional radioactive Northern blot methods while limiting the complications associated with using radioactive material. This method also enables multiplexing such that different species of RNA can be detected at the same time.