The thickness of the band, as well as the length the band of RNA has traveled during electrophoresis, indicates that the RNA of interest is present to some degree.
The thickness and darkness of the band of RNA revealed by the probe indicates the relative amount of RNA present in the sample. In addition, the length the band traveled during electrophoresis indicates the size, in kilobases (kb) of the RNA.
Northern blotting allows researchers to determine gene expression patterns. This indicates a myriad of practical applications, allowing researchers to compare patterns of gene expression in cells of tissues, cells of patients undergoing treatment and cells of different developmental stages.
Northern blot analysis can also be used to detect cancerous pancreatic cells and tissues, as indicated by Streit, Michalski, Erkan, Kleeff and Friess. In one study they review, pancreatic cancers exhibited 3-fold, 15-fold and 10-fold increases in the mRNA of a certain receptor, indicating for the first time that this receptor was involved in the carcinogenesis of pancreatic cancer.