Watch how Sanger sequencing kickstarted the first generation of DNA sequencing

See the history of DNA sequencing

DNA sequencing evolved from manual methods to automated, high-throughput technologies. The Human Genome Project was possible in the first generation of gene sequencing technology with the "chain termination method," which won developer Fredrick Sanger a Nobel Prize.

Glowing chemicals allow scientists to read DNA like a barcode

The process of determining the order of nitrogenous bases in DNA involves first cutting the DNA into fragments, which are duplicated multiple times using bacteria. Fluorescently labeled terminator bases are added to fragments, which are sorted by length and read via laser to reconstruct the sequence.

Genomic sequencing is the process of determining the order of nucleotides that make up an organism's genetic information and can be done in about 24 hours or less for human DNA.

How do you sequence a genome?

If the genome is made up of microscopic chromosomes, how do scientists actually sequence it? Here's a 5-minute video explaining one of the most common processes.

Breaking the genome into random segments accelerated the Human Genome Project

Hierarchical shotgun sequencing is a method for determining an organism's genome by fragmenting DNA before sequencing. By creating fragments with overlapping nucleotide bases, the DNA is reassembled by matching fragment ends.

See a timeline of landmark discoveries in the field of genetics to gain a better understanding of more than a century of advances.

Fully sequenced human genome will help scientists better understand disease

April marks the 20-year anniversary of the completion of the Human Genome Project, a monumental achievement that provided the first map of the human genetic code and advanced our understanding of human biology, disease, and potential treatments....

Think we decoded the genome in 2000? Nope. It was 2022.

Two decades after the draft sequence of the human genome was unveiled to great fanfare, a team of 99 scientists has finally deciphered the entire thing. They have filled in vast gaps and corrected a long list of errors in previous versions, giving us a new view of our DNA.

Visualization of printing synthetic DNA

Ever wonder how synthetic DNA is made? Discover how GenScript uses innovative technology to synthesize precise, high-quality DNA at a larger scale than ever before.

Modern genetic testing stems from a 1950s discovery about the cause of Down syndrome.

Like counting how often a word is repeated in a sentence, forensic scientists can identify people by tallying how often short segments of genetic information repeat in specific parts of a person's DNA—a set of numbers that varies from person to person.

Explore the original goals of the Human Genome Project

The project goals emphasized DNA sequencing technologies and methods, which would lead to future treatments of genetic disorders. Exploring the project data's ethical and social implications was also considered.

Nature simultaneously published three papers on DNA—only the first made history

Papers by Watson and Crick, Wilkins, and Franklin were fast-tracked without peer review, and their order was arranged between lab heads and editors. Franklin's appeared last, making her paper read as though supporting Watson and Crick—because they'd already incorporated her data before it was published.

Nineteen years after its conclusion, scientists finish what the HGP started

The Human Genome Project mapped 92% of the human genome sequence upon its completion in 2003, leaving unreachable DNA regions unmapped. PacBio HiFi DNA sequencing allowed its completion 19 years later, with the additional mapping of 200 million DNA letters.

Rosalind Franklin’s work led to Nobel Prize-winning discoveries in DNA and virology

Her X-ray diffraction imaging helped uncover the structure of DNA, which earned James Watson, Francis Crick, and Maurice Wilkins a Nobel Prize. The same techniques enabled virus imaging, contributing to Aaron Klug's Nobel Prize in chemistry.

The Human Genome Project spawned numerous spinoff genetics projects

The Human Genome Project led to the development of techniques later applied to projects in microbial and plant biology, epigenomics, environmental and cancer genomes, and more. In the spirit of the HGP, data from these projects has been made freely available to develop new technologies.

Rosalind Franklin was the long-overlooked contributor to discovering DNA's structure

Though James Watson, Francis Crick, and Maurice Wilkins are credited with discovering the DNA double helix, it incorporated Rosalind Franklin's unpublished data. Photo 51, her famous DNA image, took more than 100 hours to produce and a year’s worth of analysis to interpret.

The 2008 Nobel Prize in chemistry was awarded for discovering and developing uses for green fluorescent protein—a biomolecule found in Aequorea victoria, a jellyfish native to the Pacific Northwest.

All publicly available DNA sequences are available at GenBank

The National Institutes of Health's database stores comprehensive, annotated DNA sequences as part of the International Nucleotide Sequence Database Collaboration. It encourages unrestricted data access within the scientific community while allowing submitters to retain intellectual property rights over their data.

Photo 51's distinct 'X' pattern and spacing provided data to validate DNA's model

Rosalind Franklin and Raymond Gosling captured the photo after bombarding DNA fibers with X-rays and observing how the beams were deflected. The photo had a 62-hour exposure time and indicated a helical structure for DNA.

The discovery of the first extremophile and how it revolutionized DNA analysis

While investigating samples taken from within and around the hot springs at Yellowstone National Park, microbiologist Thomas Brock discovered Thermus aquaticus, a microorganism that thrived in hot water. It contained an enzyme called Taq polymerase, a critical molecule in polymerase chain reaction—a molecular photocopier that amplifies genetic signals to improve medical diagnostics.

X-ray data from Rosalind Franklin was key to discovering DNA’s double-helix structure

Although unpublished, the data reached James Watson and Francis Crick, who worked at another institution. Incorporating her data allowed them to validate their model of DNA, which they published without crediting her.

Watson and Crick revealed DNA's double-helix structure using others' key findings

Their 1953 model, made from cardboard cutouts, explained how DNA stores genetic information through base pairing. Rather than experimenting and collecting their own data, they incorporated patterns and data from other scientists through trial and error.

CRISPR-Cas9 enables precise genome editing using a simple RNA-guided system

Jennifer Doudna's research uncovered how bacteria use the tool as an immune defense by cutting viral DNA. She and Emmanuelle Charpentier received the 2020 Nobel Prize in chemistry for showing how this mechanism could be engineered to target and edit genes in living cells.

An overview of the Human Genome Project

The Human Genome Project was a groundbreaking global scientific effort to sequence the genome of humans and several organisms used in scientific research. The sequenced genome was created by combining the DNA of 20 people from Buffalo, New York.

See a timeline of the Human Genome Project

Despite starting on October 1, 1990, the goal of mapping all the DNA found in a human being was first planned in 1984. The project would reach its goals two years ahead of schedule in 2003.

The woman erased from the DNA breakthrough

Rosalind Franklin captured “Photo 51,” the key to DNA’s double helix. Her data, shared without her knowledge, helped Watson and Crick win a Nobel. She never got the prize, but today, her role in unlocking life’s blueprint is finally recognized.

Beyond DNA, Franklin's legacy extends into modern virology and steel production

While remembered for her critical but under-credited role in uncovering parameters for the structure of DNA, Rosalind Franklin made significant contributions across coal chemistry and virus structure. Her research helped improve fuel efficiency, wartime protective equipment, and foundational knowledge in molecular biology.

Bacteria helped scientists realize that DNA was the hereditary molecule, not proteins

Until the mid-1900s, most scientists believed genes were made of proteins, which were known to act as enzymes, hormones, and other chemicals that mediated an organism's traits. The Avery-MacLeod-McCarty and that benign bacteria could be made lethal, where the inherited factor that caused bacterial transformation contained DNA.

The $3B project scientists called 'junk'

In 1990, scientists set out to map all of human DNA. A $3B bet many called "junk." But the Human Genome Project's radical transparency and a race with a private company sped it to completion in just 13 years. Today, that once-contested map underpins nearly every breakthrough in genetics and personalized medicine.

Synthetic biology transforms cells into custom DNA foundries

At companies like Ginkgo Bioworks, researchers are reprogramming cells to act as workshops that can create custom molecules, such as medicines and fertilizers, by stitching together DNA sequences—often in novel combinations—before inserting them into an organism's genome.

Ancestry testing matches DNA to known genetic variants found in specific ancestries

After a lab receives a person's sample, the DNA is separated into single strands, which are chemically cut into smaller fragments. The fragments are then fed into an array of variants of known origins, and technicians observe if a person's fragments bind to specific variants.

The Human Genome Project was forced to accelerate due to a private competitor

Despite a 15-year target when it began in 1990, the Human Genome Project faced competition from Celera Genomics when it entered the sequencing race in 1998. Celera's aim to complete the human genome in three years pressured the HGP to complete their sequencing several years ahead of schedule.

Watch how proteins are created from DNA

When a DNA sequence—a gene—is activated, a copy of the activated portion is created in the form of RNA, a single-stranded version of DNA, in a process known as transcription. This RNA, called messenger RNA, leaves the nucleus and travels to a ribosome, a structure within a cell, which uses it to build a chain of organic compounds that fold into a protein.

Strands of DNA can act as biochemical Velcro and fasten two molecules together because the complementary bases that make up DNA strands bond together consistently.

View a collection of historical documents about molecular biology's history

The collection features materials related to those involved in the discovery of DNA and provides historical context for the discoveries of RNA, various viruses, and important bioproteins. The items include photographs, business correspondence, manuscripts, and scientific instruments.

A fascinating look at how our DNA is built and replicated

This easy-to-understand 13-minute video dives into the wondrous molecule deoxyribonucleic acid – also known as DNA – and explains how it replicates itself in our cells.

See how a novel gene editing technique called base editing can create changes in a single DNA base, using a more precise targeting approach than CRISPR-Cas9.

Storing data in DNA requires converting binary code into DNA's four-base system

Researchers have suggested that DNA's ability to form compact, dense structures justifies investigating its use for long-term, safe data archiving. This system could fit all of the world's data in a single shoebox, though processing each bit into a nucleotide base takes 2 minutes, as of 2024.

The pharmaceutical industry evolved, in part, from the discovery of synthetic dyes

In 1856, a chemist accidentally discovered mauveine, the world's first synthetic dye, while trying to make quinine to treat malaria. The synthetic dyes that followed helped reveal germs under microscopes, paving the way for modern imaging techniques and breakthrough treatments, such as antibiotics.

Stacking nucleotide molecules like toy blocks helps build DNA's structure

Each nucleotide is made up of a sugar—deoxyribose—a phosphate group, and one of four bases that contain nitrogen. Like building a two-tone, spiral staircase from the ground up, nucleotides are linked one on top of another so that sugars and phosphates alternate. The twisted strands are held together by hydrogen bonds between base pairs.

CRISPR turns 10 years old

When Dr. Jennifer Doudna and colleagues released a paper in 2012 demonstrating the ability to harness the cell's natural immunity machinery to edit DNA, it received little fanfare. A decade later, the gene editing technology has led to innovations in medicine, evolution, and agriculture—and raised profound ethical questions about altering human DNA.

Different enzymes can be used in the CRISPR system to modify how DNA is cut

The system uses RNA sequences to guide enzymes like Cas9 to specific spots in DNA, where they cut or modify genes. Unlike Cas9, the Cpf1 enzyme makes staggered cuts, which helps insert new DNA more cleanly.

The oldest DNA recovered so far is 2 million years old

The oldest DNA recovered so far is about 2 million years old and has given scientists an unadulterated peek into ancient history. This nine-minute video explores the findings and implications of the DNA, which was pulled from frozen soil in...

DNA computing allows for storage and processing of massive amounts of data

Although costly and less efficient for simpler tasks, as of 2025, DNA could hold 455 exabytes of data with near limitless parallel computation potential in small data centers. Every movie ever made would fit inside the volume of a single sugar cube.

In 2025, researchers in the UK began working on developing artificial DNA

The Synthetic Human Genome Project aims to one day construct human DNA, molecule by molecule, in the hopes of creating disease-resistant cells and synthetic chromosomes for study. However, critics warn it may be misused to create enhanced or modified humans.

Scientists can tag distinct proteins with fluorescent probes that emit different colors, allowing them to visualize multiple biochemical processes simultaneously.

DNA's four-letter blueprint makes the variety of all living things possible

The proteins responsible for cellular functions and an organism's traits are built outside of a cell's nucleus from RNA—single-stranded molecules created by reading the information in DNA. DNA's double-stranded structure makes it more stable and allows RNA to be made from either of its complementary strands.

Genes are the basic units of heredity

These segments of DNA—long molecules made of nucleotides that coil into chromosomes—code instructions for making specific proteins, which correspond to different traits. Approximately 98 to 99% of human DNA is non-coding, with functions beyond protein synthesis.

Homology-directed repair is the DNA repair method used by cells

Environmental factors like X-ray exposure may break a strand of DNA, but cells can use a sister strand to patch the damage. Scientists exploit this system by introducing custom DNA templates, which cells use instead to make repairs.