The Clinical Measurement Ontology (CMO), Measurement Methods Ontology (MMO), and Experimental Condition Ontology (XCO) are currently being developed at the Rat Genome Database. For more information about these vocabularies please see Shimoyama et al. Three ontologies to define phenotype measurement data. Front Genet. 2012;3:87. Epub 2012 May 28 or contact us (http://rgd.mcw.edu/contact/index.shtml).
The amount in a specified sample of blood of one or more types of immunoglobulin M (IgM), one of the five classes of antibodies produced by the body. IgM is found in circulating body fluids and is the first class of antibodies to appear in response to an initial exposure to an antigen.