Mouse Unit (MU or U) : An unofficial unit of toxicity used in pharmacology. A mouse unit is the dose of a toxin that kills 50% of mice (that is, it is the LD50
Russ Rowlett (Director), How Many? A Dictionary of Units of Measurement, Center for Mathematics and Science Education University of North Carolina, USA 2005. http://www.unc.edu/~rowlett/units/dictA.html, (Unit of Meas and Covr Factors - Amer) {608}