Northern blots are mostly a tool in RNA (ribonucleic acid) research. The RNA is extracted from the specimen and run on a gel for electrophoresis that is then transferred to a filter membrane. The type of RNA that is used in Northern blots is mRNA (messenger RNA), the product of DNA transcription.
Interpreting the results of the Northern blot includes incubating the blot and washing it to remove any non-bound probe in order to visualise the bound probe.
Transfer the mRNA strand from the gel to the membrane. Incubate the strand with a probe solution homologous to the mRNA you are using. The probe contains an indicator of your RNA of interest in order to visualise later. If the base pairs of the probe are complementary, the probe will attach to your mRNA.
Wash the mRNA strand with RNase free low and high stringency wash buffers to remove any non-bound probe.
Look for a band that forms. If a band forms, that indicates that the mRNA is homologous to the probe. If no band forms, that indicates that it is not homologous. These results will indicate in which type of cells or tissues your RNA of interest is the most abundant.