The effect of the inclusion of EDTA and of heparin, in media used in the isolation of mitochondria, on the mitochindrial ribosome has been investigated. 1. Mitochondria isolated from Neurospora crassa in the presence of EDTA contain only a single type of monomeric ribosome, viz. 73 S. 2. Mitochondria isolated in the presence of Mg 2÷ contain both 79-S and 73-S monomeric ribosomes. The heterogen...
