RNA sequencing (RNA-Seq) is a technique used to analyze the transcriptome, or the set of RNA molecules present in a cell at a given time. It provides insight into which genes are being expressed and at what levels.
How it works:
RNA is first extracted from cells or tissues and then converted into complementary DNA (cDNA) using reverse transcriptase. The cDNA is then sequenced using next-generation sequencing technology. Millions of short sequence reads are generated and mapped back to a reference genome or transcriptome to determine the origin and abundance of each RNA transcript.
Applications:
Measuring gene expression levels across conditions or time points
Identifying differentially expressed genes in disease vs. normal states
Discovering new transcripts, splice variants, or non-coding RNAs
Characterizing the effects of mutations or treatments on gene activity
How to interpret data:
RNA-Seq data is often visualized as read counts or coverage plots aligned to genes. Higher read counts indicate higher gene expression. Bioinformatics tools are used to compare gene expression between samples and identify statistically significant changes.