Technical and biological variance structure in mRNA-Seq data

mRNA expression data from next generation sequencing platforms is obtained in the form of counts per gene or exon. Counts are generally assumed to follow a Poisson distribution in which the variance is equal to the mean. However, it is common in observed count data with biological variation for over-dispersion to be present, i.e., for the variance to be greater than the mean. examination of technical and biological variance in mRNA-seq count data