Analysis of Gene Expression at the Functional Genomic Level Using Northern Blotting or PCR

Northern blot hybridization is a procedure in which different sizes of RNA molecules are separated in an agarose gel, immobilized onto a solid support of either nylon or nitrocellulose membranes, and then subjected to hybridization with a labeled DNA or RNA probe. Unlike the Southern blotting technique that involves DNA-DNA hybridization, northern blot hybridization refers to RNA-DNA or RNA-RNA hybridization. Technically, northern is not a person’s name; nor is it due to a geographic location. As a matter of fact, this technique was developed later than the Southern blot method, and so named the northern blot method.