We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What Is Green Fluorescent Protein?

By Phil Riddel
Updated May 21, 2024
Our promise to you
All The Science is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At All The Science, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject-matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

Green fluorescent protein (GFP) is protein that occurs in a species of jellyfish, Aequorea victoria, which is found in the North Pacific. Fluorescence is a phenomenon whereby certain substances absorb energy from electromagnetic radiation, such as light, and emit the energy at a different, normally longer, wavelength. The green glow produced by GFP results from it absorbing relatively high-energy blue and ultraviolet light and emitting it as green light, which has a longer wavelength and less energy; it will therefore glow green when exposed to invisible ultraviolet light. GFP is of particular interest to biologists as, unlike most other fluorescent proteins, it fluoresces by itself without the requirement for any interaction with other molecules. Since it is a protein made up entirely of amino acids, this means that organisms can be genetically engineered to produce it, giving rise to a wide range of applications in various fields of biology.

Bioluminescence occurs in many marine organisms. In the case of Aequorea victoria, a chemiluminescent substance called aequorin emits blue light when it combines with calcium ions. This light is then absorbed by the green fluorescent protein to produce a green glow. A number of other marine organisms have been found to contain these substances, but it is not clear why they have evolved to produce this glow or to change the color from blue to green. One suggestion, based on experimental evidence that glowing GFP can release electrons, is that GFP could act as a light-activated electron donor, in a similar way to chlorophyll in green plants.

The green fluorescent protein has a complex structure. The fluorescent part — known as a fluorescent chromophore — consists of three amino acids, tyrosine, glycine and either serine or threonine, joined in a ring shape. This is contained within a cylindrical structure that protects the chromophore from contact with other molecules, a feature that is crucial to the fluorescence, as contact with water molecules would otherwise dissipate the energy used to produce the green glow.

GFP has proved to be extremely useful in fields such as genetics, developmental biology, microbiology and neurology. It can be used for tagging specific proteins within an organism in order to see where and when they are expressed; the part of the organism’s DNA that codes for the protein of interest can be engineered to also synthesize GFP, thus allowing tracking of the protein within living cells using ultraviolet light. Viruses can also be tagged in this way, allowing infections in living organisms to be monitored. Green fluorescent protein can also be modified to fluoresce in several other colors, opening up new possibilities. One of these has been the creation of transgenic mice with varying combinations of fluorescent proteins expressed in neurons, which allow neural pathways in the brain to be studied in detail.

Other applications have been found outside biology. One controversial development is the engineering of fluorescent pets. Genetically engineered animals that produce green fluorescent protein have been created, and include fish, rats, pigs and a rabbit.

All The Science is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Discussion Comments
All The Science, in your inbox

Our latest articles, guides, and more, delivered daily.

All The Science, in your inbox

Our latest articles, guides, and more, delivered daily.