I am quite new in the topic of next generation sequencing. I am trying to find the best extraction method of small RNAs. The idea is to compare different extraction methods by sRNAseq. I wonder what would be the best criteria then. I am not sure if the number of mapping reads is enough. I should look at the coverage on the exon intron and intergenic regions. Any other suggestions or link to some papers where I can find more info?