Distribution of HP1α, 3metH3K9 proteins and 5metC in human CLL cells. Representative images are shown for the localization of HP1α (a-x). All cells were stained with DAPI (blue) (a,e,i,m,q,u). Cells were stained with a polyclonal antibody against 3metH3K9 (red) (b,f,j,n,r,v) a marker of inactive chromatin and antibody against HP1α (green) (c,g,k,o,s,w) a marker of heterochromatin. Merged images show the co-localization of these two proteins. Labeling with a 5metC antibody (green) (1-6) revealed a global hypomethylation state and a more diffuse pattern in CLL cells (1-4) vs. control cells (5-6). Scale bar, 2 μm.