Anti-M31 antibodies are protein reagents that detect specific antigens. The M31 antigen is another term for the human protein chromobox 1, encoded by the CBX1 gene. The protein is known to be a component of heterochromatin. Canonically, it has an amino acid length of 185 residues and a mass of 21.4 kilodaltons. Its subcellular localization is in the nucleus and it is reported to be expressed in all adult and embryonic tissues. Other alias names for M31 include CBX, CBX, and HP1-BETA. Western Blot is a widely used application for the M31 antibodies listed below. In addition, ELISA is also a common application.