Immunostaining analysis of tissue cultured cells and tissue sections using phospho-Histone H3 (Serine 10) antibody

Post-translational modifications of histones play an important role in regulation of gene expression through condensation and decondensation of chromatin structure. These modifications include acetylation, methylation, phosphorylation and ubiquitination. Phosphorylation on histones is associated with cellular responses such as DNA damage, transcription, chromatin compaction and mitosis or meiosis. One of the most extensively studied modifications of histones is the Serine 10 phosphorylation on histone H3 N-terminal tail. This specific phosphorylation on Histone H3 has been associated with condensation and transcriptional inactivation of mitotic chromosomes, but recent studies have suggested a role for this specific phosphorylation in chromatin relaxation and activation of transcription in interphase cells. Co-immunostaining analysis of cells using antibodies specific to serine 10P-Histone H3 together with those to cell cycle specific markers will allow us to determine the nature of phosphorylation in a cell cycle-specific manner. In a complex system, such as tissue specimens, analysis using P-Histone H3 and a cell type specific antibody will allow identification of specific cells that are affected by this histone modification. This is of particular interest in the field of cancer biology or neurobiology where identification or quantification of the transcriptionally active or mitotic cells will enable one to evaluate the progression of the disease development. The protocol described here provides details on how co-immunostaining and analysis can be performed in tissue cultured cells or tissue sections.