to irreversibly freeze the status quo of interaction , either testosterone , the physiological ligand , or diazo-mapd ( 21-diazo-4-methyl-4-aza-5 alpha-pregnane-3,20-dione ) , a specific 5 alpha-reductase inhibitor , was irradiated with isolated nuclei or with purified nuclear membranes or with solubilized nuclear membrane proteins and checked for optimal labelling conditions .
C0007610
nuclei
C0028584
nuclear membranes