RNases are ubiquitous and can often contaminate and subsequently degrade RNA samples in the laboratory, so RNA integrity can very easily be compromised, leading to a number of laboratory techniques designed to eliminate their impact. However, these methods are not fool-proof, and so samples can still be degraded, necessitating a method of measuring RNA integrity to ensure the trustworthiness and reproducibility of molecular assays, as RNA integrity is critical for proper results in gene expression studies, such as microarray analysis, Northern blots, or quantitative real-time PCR (qPCR). RNA that has been degraded has a direct impact on calculated expression levels, often leading to significantly decreased apparent expression.
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 qPCRs accuracy and reproducibility for gene expression and other applications. RIN assessment allows a scientist to evaluate an experiments trustworthiness and reproducibility before incurring substantial costs in performing the gene expression studies.
RIN is a standard method of measuring RNA integrity and can be used to evaluate the quality of RNA produced by new RNA isolation techniques.