<P> qPCR and similar techniques are very expensive, taking a good deal of both time and money, so continuing research being undertaken to decrease the cost while maintaining qPCR's accuracy and reproducibility for gene expression and other applications . RIN assessment allows a scientist to evaluate an experiment's trustworthiness and reproducibility before incurring substantial costs in performing the gene expression studies . </P> <P> RIN has become a standard method of measuring integrity, even in meta - analyses such as "Efficient extraction of small and large RNAs in bacteria for excellent total RNA sequencing and comprehensive transcriptome analysis", wherein the authors analyzed a number of different RNA extraction methods, using the resultant RIN as a measure of their efficiency at producing high - quality RNA . RIN has also been used to test the efficiency of other techniques, such as microdissections, on maintaining RNA integrity in human cells, so it has a wide variety of uses in testing the quality of new techniques . RIN has become an industry standard to test various methods for the quality of their produced RNA, and it is also used in a wide variety of non-meta analyses so that the scientists are able to ensure that the quality of their RNA is trustworthy and their results are thus sound, often with a benchmark minimal RIN being used as a standard to ensure all of their RNA is high enough quality to yield reliable findings . </P> <P> As RNA integrity has long been known to be a problem in molecular biology studies, there are a few methods that have been used historically to determine the integrity of RNA . The most popular has long been agarose gel electrophoresis with ethidium bromide staining, allowing one to visualize the bands from the rRNA peaks . The height of the 28S and 18S bands can be compared to each other, with a 2: 1 ratio indicating non-degraded RNA . While this method is very cheap and easy, there are several issues with this method, primarily its subjectivity, leading to inconsistent, non-standardized RNA quality assessments, and the large amounts of RNA that are needed to visualize it on an agarose gel, which can be problematic if there is not much RNA to work with . There are also a number of different problems that can arise from agarose gel electrophoresis, such as poor loading, uneven running, and uneven staining that lead to increased variability in the accuracy of using agarose gel electrophoresis to determine RNA integrity . Clearly, a standardized, repeatable, objective method of determining RNA integrity was needed . </P> <P> Agilent Technologies sought to create one, and so created the RNA Integrity Number . The algorithm was generated by taking hundreds of samples and having specialists manually assign them all a value of 1 to 10 based on their integrity, with 10 being the highest . Adaptive learning tools using a Bayesian learning technique were used to generate an algorithm that could predict the RIN, predominantly by using the features listed below under "Computation". This allows for all Agilent software to produce the same RIN for a given RNA sample, standardizing the measurement and making it much less subjective than earlier methods . </P>

The rin an rna integrity number for assigning integrity values to rna measurements