noun nuclein (biochemistry) A phosphorus-rich protein found in the nucleus of a cell, later specifically nucleohistone or nucleoprotamine; also, any similar compound present in the cell nucleus. (from 19th c.). 1
noun nuclein any of a group of proteins, containing phosphorus, that occur in the nuclei of living cells 0
noun nuclein any of a group of decomposition substances found in the nuclei of cells that are intermediate to nucleoproteins and nucleic acids 0
