In the papers I read, it is usually claimed that since RNA-Seq is count data, a Poisson or negative binomial distribution would be the most suitable ones to model the RNA-Seq data. However, as a computational biologist, none of the RNA-Seq data I have seen so far is composed of integers. All RNA-Seq datasets I have seen contain decimals, which is probably because there is a standard normalization process applied to the raw read counts, which is crucial. This normalization process usually adjusts for sequencing depth and also for overdispersion. So, my question is, how come we can model those decimal numbers with Poisson or negative binomial? As I said, I have never seen processed (or normalized) RNA-Seq data that contain integers. What am I missing?
