CST's PathScan^® Phospho-Histone H3 (Ser10) Sandwich ELISA Kit is a solid phase sandwich enzyme-linked immunosorbent assay (ELISA) that detects endogenous levels of Phospho-Histone H3 (Ser10) protein. A Histone H3 Antibody has been coated onto the microwells. After incubation with cell lysates, both nonphospho- and phospho-Histone H3 proteins are captured by the coated antibody. Following extensive washing, a Biotinylated Phospho-Histone H3 (Ser10) Antibody is added to detect the captured phospho-Histone H3 (Ser10) protein. HRP-linked Streptavidin is then used to recognize the bound detection antibody. HRP substrate, TMB, is added to develop color. The magnitude of optical density for this developed color is proportional to the quantity of Phospho-Histone H3 (Ser10) protein.

*Antibodies in kit are custom formulations specific to kit.

CST's PathScan^® Phospho-Histone H3 (Ser10) Sandwich ELISA Kit detects endogenous levels of Phospho-Histone H3 (Ser10). Using this Sandwich ELISA Kit #7155, Phospho-Histone H3 (Ser10) is detected when treated with Calyculin A in NIH/3T3 cells. However, the levels of Histone H3 remains unchanged, as shown by western analysis using the Histone H3 Antibody #9715 (Figure 1). 293 cells treated with Calyculin A show similar results (data not shown). This kit detects proteins from the indicated species, as determined through in-house testing, but may also detect homologous proteins from other species.

Modulation of chromatin structure plays an important role in the regulation of transcription in eukaryotes. The nucleosome, made up of DNA wound around eight core histone proteins (two each of H2A, H2B, H3, and H4), is the primary building block of chromatin (1). The amino-terminal tails of core histones undergo various posttranslational modifications, including acetylation, phosphorylation, methylation, and ubiquitination (2-5). These modifications occur in response to various stimuli and have a direct effect on the accessibility of chromatin to transcription factors and, therefore, gene expression (6). In most species, histone H2B is primarily acetylated at Lys5, 12, 15, and 20 (4,7). Histone H3 is primarily acetylated at Lys9, 14, 18, 23, 27, and 56. Acetylation of H3 at Lys9 appears to have a dominant role in histone deposition and chromatin assembly in some organisms (2,3). Phosphorylation at Ser10, Ser28, and Thr11 of histone H3 is tightly correlated with chromosome condensation during both mitosis and meiosis (8-10). Phosphorylation at Thr3 of histone H3 is highly conserved among many species and is catalyzed by the kinase haspin. Immunostaining with phospho-specific antibodies in mammalian cells reveals mitotic phosphorylation at Thr3 of H3 in prophase and its dephosphorylation during anaphase (11).