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).
A homogeneous mixture of molecules, atoms and/or ions, one or more of which have the capacity to cause the solution to resist change in pH upon addition of small amounts of acid or base, dispersed molecularly in a sufficient quantity of dissolving medium (solvent) such as water.