A lysin that is formed in one species of animal and manifests lytic activity on the cells of a different species. ... (05 Mar 2000) ... 
(het″әr-ol´ĭ-sin) an antibody that lyzes cells of species other than the one in which it is formed.
Type: Term Pronunciation: het′ĕr-ol′i-sin Definitions: 1. A lysin that is formed in one species of animal and manifests lytic activity on the cells of a different species.