Histone H3
Histones are highly basic proteins that complex with DNA to form chromatin. H3 histone Flow cytometry may be used to analyse cell cycle with propidium iodide (PI) giving peaks of G1 and G2m with S phase located between these peaks. Labelling histone H3 with a fluorescently conjugated monoclonal antibody and then staining PI allows the investigator to determine which G2m cells are in the m phase of the cell cycle by flow cytometry.