RNA, the single-stranded nucleic acid that carries and executes genetic instructions

RNA (ribonucleic acid) is single-stranded nucleic acid essential for information transfer (mRNA), catalysis (ribozymes), translation (tRNA, rRNA), and gene regulation (miRNA, siRNA, lncRNA). Explore the full definition and applications on this page.

RNA is closely connected to mRNA and other Sequencing concepts. Understanding these relationships is essential for comprehensive knowledge in molecular biology and bioinformatics.

VigyanLLM's 24-step validated pipeline incorporates RNA as part of its rigorous quality control framework. The platform automates checks related to RNA to ensure primer design accuracy, specificity, and reliability for research and clinical applications.

The main types include messenger RNA (mRNA) which carries protein-coding information, transfer RNA (tRNA) which brings amino acids during translation, ribosomal RNA (rRNA) which forms the structural core of ribosomes, microRNA (miRNA) which regulates gene expression post-transcriptionally, small interfering RNA (siRNA) involved in RNA interference, and long non-coding RNA (lncRNA) with diverse regulatory functions.

Pre-mRNA is the initial transcript synthesized from DNA during transcription, containing both exons (coding regions) and introns (non-coding regions). mRNA is the mature form after splicing removes introns and adds a 5-prime cap and poly-A tail. Only mature mRNA is exported from the nucleus to the cytoplasm for translation into protein.

RNA is extracted using guanidinium isothiocyanate-phenol-chloroform methods (TRIzol) or silica membrane column-based kits (Qiagen RNeasy). Cells are lysed in a denaturing buffer that inactivates RNases, RNA is separated from DNA and proteins by phase separation or column binding, washed, and eluted in RNase-free water. Samples must be kept on ice and treated with DNase to remove genomic DNA.

Reverse transcription converts RNA into complementary DNA (cDNA) using the enzyme reverse transcriptase. This is essential for studying RNA by DNA-based methods like PCR and sequencing, since DNA polymerases cannot use RNA as a template. RT-PCR, RNA-seq, and cDNA library construction all depend on reverse transcription. The enzyme was originally discovered in retroviruses.

RNAi is a biological process where small RNA molecules (siRNA or miRNA) bind to complementary mRNA sequences and trigger their degradation or block translation, thereby silencing gene expression. It is a natural regulatory mechanism conserved across eukaryotes and is harnessed experimentally to knock down specific genes for functional studies or therapeutic applications.

RNA-seq converts RNA to cDNA, sequences it on a high-throughput platform, and maps the reads to a reference genome or transcriptome. It quantifies gene expression levels, discovers novel transcripts and splice variants, identifies fusion genes, detects allele-specific expression, and reveals non-coding RNA expression. RNA-seq has largely replaced microarrays for transcriptome analysis.

RNA is degraded by RNases, which are ubiquitous enzymes present on skin, dust, and lab surfaces. Prevent degradation by using RNase-free water and tubes, wearing gloves, working in a dedicated RNA area, using RNA stabilization reagents (RNAlater), storing RNA at -80°C, and adding RNase inhibitors to reactions. RNA integrity should be verified before downstream applications.