How is GFP produced?

GFP is produced by the jellyfish Aequorea victoria, which emits bioluminescence in the green zone of visible spectrum; the protein is physically found on the organs of the jellyfish. More specifically, the jellyfish produces green bioluminescence from small organs on its umbrella portion. The rings of jellyfishes are squeezed through a rayon gauze, and a luminescent liquid called squeezate is collected. The calcium ions released from Aequorea cause the actual bioluminescence. The ions bind to a protein called aequorin, which releases blue light after becoming bound to calcium. The blue light is then absorbed by the GFP, which gives the protein its green color.