On 9 August 2007, researchers from McMaster University in Hamilton, Canada, published a paper that demonstrated the world's smallest thermometer. Made from Green Fluorescent Protein, the substance that allows jellyfish to glow, the protein emitted "flashes" of light in direct relationship to its temperature. The flashing of the protein happens very quickly and is caused by light being absorbed and emitted by the protein molecules. The protein itself is only around ~42 Å long and ~24 Å in diameter, and comprises 238 amino acids in a cylindrical arrangement. Applications in micro-surgical monitoring and non-invasive sensors for health monitoring are an obvious offshoot of this incredible technology.These proteins have been used to genetically bond to skin of mice and fish. They are demonstrated to be biologically safe in thermometer applications by experiments to show they can be attached safely to animal DNA.