Bcl-x belongs to the Bcl-2 family of proteins and plays a crucial role in apoptosis. Bcl-X has two isoforms: Bcl-XL (long), a 26 kDa protein which suppresses cell death, and Bcl-XS (short), a 178 amino acid protein lacking a 63 amino acid domain which functions as a dominant inhibitor of Bcl-2 and promotes apoptosis. This MAb reacts with both Bcl-XS and Bcl-XL proteins, and shows no cross-reaction with Bcl-2 or Bax proteins.Primary antibodies are available purified, or with a selection of fluorescent CF® Dyes and other labels. CF® Dyes offer exceptional brightness and photostability. Note: Conjugates of blue fluorescent dyes like CF®405S and CF®405M are not recommended for detecting low abundance targets, because blue dyes have lower fluorescence and can give higher non-specific background than other dye colors.