This protocol is used to dissociate adult (8-10 wk) mouse ear "on ice" (in order to reduce gene expression artifacts). The cell yield is 9000 cells/mg (213000 cells total from 23 mg tissue), with 98% viable. The protocol involves a 2-layered dissociation, incubating on ice with bacillus licheniformis enzyme. The dissociation is augmented by the use of a dounce homogenizer to help break up the tissue.