Preface

The advent of next-generation sequencing along with the development of bioinformatics tools has opened avenues to explore this technology in numerous fields of biomedical research. This book evaluates and comprehensively summarizes the scientific findings that have been achieved through RNA-sequencing (RNA-Seq) technology.

RNA-Seq allows us to accurately capture all subtypes of RNA molecules, in any sequenced organism or single-cell type, under different experimental conditions. RNA-Seq transcriptome profiling of healthy and diseased tissues allows for understanding the alterations in cellular phenotypes through the expression of differentially spliced RNA isoforms. Assessment of gene expression by RNA-Seq provides new insight into host response to pathogens, drugs, allergens, and other environmental triggers.

RNA-Seq becomes even more powerful when combined with other assays. Merging genomics and transcriptomic profiling provides novel information underlying causative DNA mutations and the cellular effects of genetic variants caused by SNPs, indels, and more. Combining RNA-Seq with immunoprecipitation and cross-linking techniques is a clever multi-omics strategy assessing transcriptional, posttranscriptional, and posttranslational levels of gene expression regulation.

The optimization of RNA-Seq technology will allow countless opportunities in our pursuit of achieving the goals of individualized medicine and public health emergency responses.

> **Irina Vlasova-St. Louis, MD, Ph.D.** COVID-19 Laboratory Associate Program, Nevada State Public Health Laboratory, Association of Public Health Laboratories, Center for Disease Control and Prevention, Reno, NV, USA

### **Chapter 1**
