when nuclear chromatin swollen in low salt buffer and extended uniformly into nucleosomal filaments is exposed to buffers containing higher concentrations of monovalent ions ( e.g. , 100 mm nacl ) or low concentrations of divalent cations ( e.g. , 0.05-0.5 mm mgcl2 ) rapid and almost complete recondensation of the entire chromatin of a nucleus into one compact spheroidal aggregate of chains of higher order granules ( diameters 25-30 nm ) is observed .
C0008546
chromatin
C0007610
nucleus