Comprehensive Review of Transcriptomics (RNAs) Workflows from Blood Specimens

ABSTRACT Blood is the most interesting tissue for molecular analysis in a wide range of diseases since it provides accumulative information of the whole body state. Transcriptomic analysis of the blood is one of the most favorable omics approaches for clinical and research purposes. However, blood sample preparation for RNA analyses is highly diverse encompassing specific methodology and application. In this study, we review the common sample preparation maneuvers including RNA handling techniques, sample collection and stabilization, blood cell sorting, extracellular vesicle enrichment, RNA extraction, globin/ribosomal RNA reduction, and RNA concentration and quality assessment. These techniques are the most prevalent procedures of blood sample preparation in RNA transcriptomic analyses. The methodologies, technical challenges of the current approaches, and latest advances in the field are discussed in detail.