Crude separation of euchromatin and heterochromatin.

(a.) Purification diagram, (b.) One-dimensional SDS-PAGE analysis of euchromatin (S1), heterochromatin (S2) and pellet fractions. Proteins in these fractions were separated by one-dimensional 15% SDS-PAGE gel and stained with Coomassie Brilliant Blue. Loading is approximately 10 ug of protein per lane, (c.) DNA gel (2% agarose) of S1, S2, and pellet fractions. S1 is composed mostly of mononucleosomes running at approximately 150 bp (black arrow). S2 and pellet fractions contain longer pieces of DNA corresponding to more compact chromatin. Total MNase digestion is shown for comparison, (d.) Venn Diagram indicating the number of proteins detected in one, two or all three fractions.