Hello Robert, there is no doubt in the preparation of nuclear extract as I do get other histones in it like H3 and H4. I get prominent band of histones with minimal (>5% cytosolic contamination - Gapdh or tubulin). I use the classic nuclear extraction protocol using triton-NP 40 buffer and the preparations have worked well in the past, though I use BCA detection system from Pierce biotechnology for protein estimation.

I found this paper. They used the ANA-108 antibody. This is not my field, but this is what came up in a google search of "H1 and brain." The abstract is interesting at least.

Journal of Neurocytology

1997, Volume 26, Issue 12, pp 823-831

Histone H1; A neuronal protein that binds bacterial lipopolysaccharide

S. J. Bolton,

V. H. Perry

Abstract

Bacterial lipopolysaccharide (LPS) is a potent inflammogen following systemic infection. Macrophages express a number of surface molecules including CD14, CD18 and the scavenger receptor that are capable of recognizing and binding LPS. Injection of the CNS with LPS produces an atypical inflammatory response including a delay in the recruitment of macrophages to the brain parenchyma. We have shown using a ligand blot overlay approach, that LPS is capable of binding to histone H1 present in brain homogenate. The ability of LPS to bind to H1 has only been previously shown for monocytes. Subsequent immunohistochemistry revealed that the anti-H1 antibody, ANA-108, stained neuronal cell bodies and was located in the membrane, possibly at the cell surface. Further experiments revealed that the H1 antigen recognized by the ANA-108 antibody was not a histone wholly restricted to the nucleus but may represent a novel CNS form of the protein. This observation has implications for the autoimmune disease systemic lupus erythematosus (SLE) due to the presence of auto-antibodies, particularly against DNA and nuclear proteins, in serum. The formation of immune complexes in various organs leads to severe dysfunction. Anti-histone antibodies are typical of the auto-antibodies found in SLE serum and the presence of the H1 antigen on the surface of neurons could provide an insight into biology underlying the neurological problems associated with SLE.