Akt, also known as protein kinase B (PKB) or Rac, is a serine/threonine kinase that is of significant interest in pharmaceutical research due to its implicated roles in cell growth, cell survival, cancer, diabetes, and neurological disorders. Activated Akt promotes growth factor-mediated cell survival by inhibiting apoptosis through several signaling pathways. An anti-apoptotic effect of Akt overexpression has been observed in breast, pancreatic, and ovarian cancer cells. Akt also regulates glycogen synthesis and may play a role in glucose uptake following insulin stimulation. The central role of Akt signaling in multiple disease conditions has created a need for immunoassays that can accurately quantify this protein in biological samples. Such quantification can be obtained with an electrochemiluminescence assay by using recombinant protein standards as calibrators as opposed to the qualitative Western blot method. To enable the accurate measurement of active Akt, MSD has developed a Phospho-Akt (Ser473) Kit that uses purified protein calibrator and provides assay-specific components for the quantitative determination of endogenous Akt phosphorylated at serine 473 in human, mouse, rat, and non-human primate cell lysates and tissue lysates. This all-inclusive kit includes the MULTI-SPOT Akt Plate, Akt Calibrator, Anti-Phospho-Akt (Ser473) Antibody, Diluent 39, Tris Wash Buffer, Read Buffer T, inhibitors, and blockers. As supplementary materials, MSD also offers the Akt Control Pack I, which includes cell lysates at two concentrations, and an Inhibitor Pack, which contains phosphatase and protease inhibitors.