A group of proteinaceous infectious pathogens known as ‘Prions’, which cause fatal neurodegenerative illnesses in man and animals, through entirely de novo mechanism. Transmissible Spongiform Encephalopathies (TSE) - a group rapidly progressive and rare fatal neurologic disease conditions caused by prions. It affects humans and mammals like sheep, goat, bovine, cattle and felines. The word ‘Prion’ was coined by Dr. Stanley B. Prusiner in 1982, which is derived from ‘protein and infection’. A Prion, is proteinaceous infectious particle, neurotropic, radiation and heat resistant, sensitive to protease, devoid of nucleic acid, forms amyloid fibrils, and has high β-helices (normal proteins are high in α-helices).