a chromatin fraction , which can reproducibly be extracted from rat liver nuclei at moderate salt concentration ( 0.1 m ( nh4 ) 2so4 , 0.1 m tris-hcl , 2 mm mncl2 , ph 7.9 ) , was analyzed with regard to changes of its molecular weight in the range of ( nh4 ) 2so4 concentrations between 0.1 m and 0.4 m .
C0008546
chromatin
C0007610
nuclei