mRNA
Americanabbreviation
Usage
What is mRNA? mRNA, or messenger RNA, is RNA that’s used to carry DNA’s genetic code outside the cell nucleus so it can be used as the instructions to build proteins. DNA is a large, complex molecule (macromolecule) that allows cells to function and carries the genetic code that determines the traits of a living organism. DNA is in every cell of every living thing and contains the instructions that cells need to function. RNA is a macromolecule that functions alongside DNA to help cells make proteins, among other functions. mRNA is created from a DNA template in the nucleus. An enzyme in the cell nucleus, known as RNA polymerase, unspirals the DNA and breaks the ladder in half down the middle. The enzyme then reads the nitrogen bases (the rungs of the ladder) and makes RNA in a process known as transcription. mRNA carries DNA’s genetic code to structures called ribosomes in the cytoplasm (the middle layer of the cell between the nucleus and the membrane). The ribosomes “read” this code (the nitrogen base sequence), which specifies the amino acid sequence for protein synthesis—the creation of proteins. Once the protein is built, the cell destroys the mRNA. We took a microscopic look at the differences between mRNA, RNA, and DNA, and their vital roles. Read all about it here!
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
The bigger promise of mRNA may be using it to prevent cancer in people at high risk, before the disease takes hold.
From The Wall Street Journal ● Aug. 23, 2026
This vaccine is different: A surgeon removes the tumor and sends it to a lab, where its mutations are sequenced and an algorithm identifies the targets for a personalized mRNA vaccine.
From The Wall Street Journal ● Aug. 23, 2026
Once injected, the LNPs protect the mRNA as it enters host cells.
From The Wall Street Journal ● Aug. 22, 2026
He told the staff that the company’s decadeslong pursuit of using mRNA to treat cancer had a major breakthrough with melanoma patients.
From The Wall Street Journal ● Aug. 22, 2026
The success of its mRNA cancer vaccine, which Moderna has been developing in partnership with Merck for a decade, has been viewed as core to Moderna’s survival.
From The Wall Street Journal ● Aug. 22, 2026
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
