Scientists Say: DNA sequencing

This process spells out the “letters” of each strand of our genes

DNA sequence

These letters and colors represent a DNA code — the chemicals that make up a strand of our genetic blueprint. Scientists can take samples using the swab from organisms and “read” their DNA through a process called DNA sequencing.


DNA sequencing (noun, “D. N. A. SEE-kwen-sing”)

Each of us has our own unique DNA — long molecules that carry instructions for how to make and run our bodies. DNA is made up of four chemicals called nucleotides. They pair up with each other to form a sequence. Those nucleotides are adenine, cytosine, guanine and thymine (or A, C, G and T). Adenine pairs up with thymine. Cytosine pairs with guanine. Our cells decode enormously long sequences of those pairings to get directions for what proteins to make.

Now, scientists can take cells from any living organism and perform DNA sequencing — matching each nucleotide up with its pair. This process allows scientists to determine exactly what each DNA strand “says.” Determining the DNA sequence helps scientists answer important questions — from what species the sample came from to what instructions the strand of DNA might contain.

In a sentence

A teen used DNA sequencing to find out which bacteria in a worm’s gut could digest plastic.

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Bethany Brookshire was a longtime staff writer at Science News Explores and is the author of the book Pests: How Humans Create Animal Villains. She has a Ph.D. in physiology and pharmacology and likes to write about neuroscience, biology, climate and more. She thinks Porgs are an invasive species.

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