The RNA integrity number (RIN) is an algorithm for assigning integrity values to RNA measurements. The integrity of RNA is a major concern for gene expression studies and traditionally has been evaluated using the 28S to 18S rRNA ratio, a method that has been shown to be inconsistent. This inconsistency arises because subjective, human interpretation is necessary to compare the 28S and 18S gel images. The RIN algorithm was devised to overcome this issue. The RIN algorithm is applied to electrophoretic RNA measurements, typically obtained using capillary gel electrophoresis, and based on a combination of different features that contribute information about the RNA integrity to provide a more universal measure. RIN has been demonstrated to be robust and reproducible in studies comparing it t