Chromatin glutaraldehyde-fixed

Unfixed or glutaraldehyde-fixed CE chromatin fibers native or LH-depleted... 

Fig. 3. Electron microscopic visualization of control and poly(ADP-ribosyl)ated native chromatin, HI-depleted chromatin and core particles. Following poly(ADP-ribosyl)ation at 200 yM NAD as described in the legend of Fig. 1, the samples were diluted to 0.01 OD unit at 260 nm and fixed for 1 h at 20 C in buffer containing 40 mM NaCl, 10 vaM TEACL, 0.2 mM EDTA and 0.1% (v/v) glutaraldehyde and processed for electron microscopy according to Poirier et al. [6]. Control native chromatin, Hl-depleted chromatin and core particles (a-c). Poly(ADP-ribosyl)ated native chromatin, Hl-depleted chromatin and core particles (d-f). Notice the dissociation of the DNA from the nucleosome cores in the poly(ADP-ribosyl)ated core particles. Also notice the relaxation of chromatin structure in the native chromatin. Big arrows indicate the automodified enzyme and small arrows indicate the DNA (145 bp) free after poly(ADP-ribosyl)ation. Th bars indicate 1000 A...

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