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.

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.

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 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.

Watch how Sanger sequencing kickstarted the first generation of DNA sequencing

Sanger sequencing is a foundational DNA sequencing technology developed in 1977. The Nobel Prize-winning discovery uses fluorescent dyes at the end of DNA chains, which are sorted by length through electrophoresis, to determine the order of nucleotide bases.

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.

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.

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.

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.

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.

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.

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.

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....

Watch DNA replicate itself before cell division

In the average adult human, between 50 billion and 70 billion cells die daily, requiring them to replicate their genetic instructions before dividing into new cells. This process relies on various proteins to unwind, read, build, and proofread new strands, with error rates of fewer than one per 1 billion nucleotides.

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.

Cells translate genetic information into proteins using RNA messengers

Genes are segments of DNA, each composed of a sequence of nitrogenous bases. Within the nucleus, these sequences are copied into a single strand of ribonucleic acid during transcription. This strand leaves the nucleus and is translated by ribosomes into a chain of amino acids that folds into a functional protein.

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.

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.

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 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.

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.

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.

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.

All humans share 99.9% of the same DNA

Of the 3 billion base pairs that make up the human genome—the complete set of genetic material for the species—the diversity of humans is the result of variations in about 3 million molecular bases. The closest nonhuman genetic match is the chimp, with 98.8% similar genetics.

Around 5 million of our 3 billion DNA letters differ between individuals

Genetic testing examines gene variants to help explain disease symptoms. It explores how genetic differences between individuals can be used to understand risks of developing diseases like Huntington's Disease or passing variants linked to disease onto offspring.

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.

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.

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.

The first criminal conviction through the use of DNA evidence was in 1988

Chromosomes contain markers where short DNA sequences repeat a variable number of times from person to person. A DNA profile is constructed by identifying the number of repeats across 20 regions throughout a genome, which can be compared against a database. DNA paternity tests work similarly by comparing markers between children and their fathers. (Some readers may experience a paywall.)

Watch how DNA is packaged to a 10,000th of its original size in a cell

In humans, the 2-meter (6.56-foot) molecule wraps around spool-like proteins called histones, forming beads—nucleosomes—that fold up into fibers. These fibers—chromatin—form loops through folding that compress into larger fibers, which tightly coil together to form a chromosome.

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.

Despite privacy risks, scientists are using DNA in the air to assess ecosystem health

While DNA in soil and water samples has long been used for such analyses, airborne DNA is being incorporated into such efforts to monitor individual species abundance, detect invasive species, measure biodiversity, and determine the success of conservation actions. Future work may include detecting attacks from biological weapons.

The Human Genome Project met its goals, but its outcomes were overpromised

The Human Genome Project aimed to sequence the entire human genome, and initial hype suggested it would revolutionize disease treatment. In reality, the project's outcomes were more nuanced, failing to deliver immediate cures despite advancing the understanding of genetics.

See a timeline of landmark discoveries in the field of genetics

From the first genetic map of fruit fly genes in 1911 through the completion of the Human Genome Project in 2003, scientists have built upon each other's discoveries to further our knowledge of the human body and the genetic instructions that inform our traits and disease risks.

The average cell's DNA is damaged thousands of times daily

In the case of radiation-induced distortions in a DNA strand, specialized proteins can cut out entire segments and rebuild them using the second strand as a complementary template. If both DNA strands are completely severed, proteins interlace undamaged DNA with the severed DNA and rebuild both using complementary base pairing.

Only 2% of human DNA codes for proteins

The entire human genome contains about 20,000 protein-coding genes, with the rest having initially been categorized as "junk" DNA. However, research since 2003 suggests that this "dark genome" regulates how protein-coding genes are expressed in response to environmental factors encountered by cells.

DNA carries the unique instructions that shape how each person grows and functions

The human genome contains over six billion DNA letters, organized into 46 chromosomes inherited from both parents. Genes—sections of DNA—serve as templates for making proteins, and variations in these sequences can affect how our bodies work or respond to the environment.

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.

Where do genes come from?

There are many more genes on Earth today than when microbial life first spawned on the planet about four billion years ago. Many of these newer genes grew from genetic mutations, misprints that slowly drift from the original blueprint via cellular division. If these mutations drift far enough, they can establish a new family of genes, though this process can take well over a million years.

Changing a single letter in DNA can permanently alter an organism

Genetic mutations occur when cells replicate, which requires a copy of DNA to be created, and involve substituting, deleting, or inserting letters in a cell's genetic code. Mutations can be caused by normal cellular processes, chemical exposure (e.g., carcinogens), or radiation and may result in genetic disorders or genetic variations that drive evolution.

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...

Recombinant DNA technology turns microorganisms into protein factories

Genes for molecules such as insulin can be inserted into loops of bacterial DNA called plasmids and reinserted into bacteria. Once placed in fermentation tanks, these bacteria use the gene to produce these molecules, which are then harvested and purified for eventual use.

About 70% of the Human Genome Project's reference genome came from one donor

Volunteers who donated blood to the Human Genome Project consented to using no more than 10% of their DNA, raising questions about the project's legality. Listen to how pressure from a private competitor may have driven officials to ignore ethical standards.

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.

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.

Model organisms like yeast, mice, and flies help scientists decode the human body

Some species are used to quickly study the effects of human diseases and treatments because they are short-lived and have similar systems to those found in humans. Bacteria, like E. coli, have been used as human proxies given their rapid growth and ease of genetic manipulability.

Explore different living beings' sizes, from DNA to whales and the Pando clone

The Pando is actually a single organism in Utah, comprising more than 47,000 stems connected by a vast root system. It spans roughly 108 acres. Meanwhile, the average human stands at 5 feet and 7 inches. DNA, the genetic instructions for life, stands at a height of 3.5 nanometers.

Visualize how CRISPR-Cas9—a type of immune system used by single-celled organisms to attack invasive viruses—targets and makes precise changes to a gene's DNA.

Take a 360-degree look at biochemical activity from within a human cell

In this tour, users can observe the dynamic processes that occur within the basic units of the human body, including the production and transport of proteins and the assembly and disassembly of microtubules—thin, cylindrical structures that provide structural support and a means of moving material within the cell.

Studies estimating the number of years between human generations suggest there have been approximately 10,000 to 12,000 generations of humans.