Northern blotting is a popular molecular biology technique that is used to detect RNA molecules. It is also known as Northern hybridization, RNA blotting, and electrophoretic separation of RNA. The technique is used to understand gene expression, RNA structure, and RNA processing. Other synonyms for the Northern blot technique include RNA electrophoresis and RNA dot blot. The technique is similar to Southern blotting, which is used to detect DNA molecules. In addition, there are variations of Northern blotting, including quantitative Northern blotting, ribonuclease protection assay, and reverse transcription polymerase chain reaction. These techniques have helped scientists unravel the complexities of RNA and gene expression and represent an essential tool in molecular biology research.