Introduction to Green Fluorescent protein

Glowing proteins - a guiding star for biochemistry

The remarkable brightly glowing green fluorescent protein, GFP, was first observed in the beautiful jellyfish, Aequorea victoria in 1962. Since then, this protein has become one of the most important tools used in contemporary bioscience. With the aid of GFP, researchers have developed ways to watch processes that were previously invisible, such as the development of nerve cells in the brain or how cancer cells spread.


Green fluorescent protein has a barrel structure, and in the middle of the barrel are a few amino acids (orange) that are involved in the colour forming reaction. Researchers have been able to alter the fluorescent colour from green to red, blue and yellow. This enables multiple proteins to be tagged at the same time and is useful for investigating interactions. The GFP "barrel" is a relative small protein and it tags easily onto either the beginning or end of the protein with as little disturbance as possible. To use a (poor) analogy, it is akin to hitching a bright green trailer (the GFP) onto a car (the protein of interest) - the trailer will follow where the car takes it. Once a fusion protein is made, it can be visualised in live cells by microscopy techniques as shown in this video.

The 2008 Nobel Prize in Chemistry rewarded the initial discovery of GFP and a series of important developments which have led to its use as a tagging tool in bioscience. By using DNA technology, researchers can now connect GFP to other interesting, but otherwise invisible, proteins. This glowing marker allows them to watch the movements, positions and interactions of the tagged proteins.

Researchers can also follow the fate of various cells with the help of GFP: nerve cell damage during Alzheimer's Disease or how insulin-producing beta cells are created in the pancreas of a growing embryo. In one spectacular experiment, researchers succeeded in tagging different nerve cells in the brain of a mouse with a kaleidoscope of colours.

For more on the discovery of GFP and some of its uses, see the Nobel prize website.


Exercise 1: Cloning Vector
Exercise 2: Human Proinsulin
Exercise 3: Cloning Primer Design
Exercise 4: Introduce Cut Site using PCR
Exercise 5: Insert into Vector