<prompt> What is a confirmatory test for Species of Origin ?Origin TestOuchterlony TestOlympus TestSOO Test  <response>: The Ouchterlony Test is an immunodiffusion test. An agar plate which is a gel is made up with a series of wells in the shape of a circle surrounding a central well. The typical setup is that the central well contains an anti -sera for human blood and the wells surrounding the central well are unknown samples. They all diffuse through the gel. Anything that is not human blood will not react with the anti -sera. If a sample is human blood then a precipitation line is formed. Ref : Krishnan vij Textbook of Forensic medicine and Toxicology 5th edtion ; researchgate.net 