it has been previously shown that micrococcal nuclease digestion and subsequent fractionation of hen oviduct nuclei generates fractions enriched ( first supernatant fraction - 1sf ) and depleted ( second supernatant fraction - 2sf ) in ovalbumin genes , while a third fraction , the pellet fraction , contains about the same level of this gene as whole chromatin ( bloom and anderson ( 1978 ) cell 15 , 141-150 ) .
C0007610
nuclei
C0008546
chromatin