Description_x000D_ General description_x000D_ SILu™MAb Mouse is a recombinant, stable isotope-labeled, mouse monoclonal antibody which incorporates [13C6, 15N4]-Arginine and [13C6, 15N2]-Lysine. Expressed in CHO cells, SILu™MAb Mouse is designed to be used as a universal internal standard for bioanalysis of monoclonal murine antibodies in animal pharmacokinetics (PK) studies._x000D_ SILu™MAb Mouse is an IgG1 antibody with a kappa light chain. Because of overlap with common sequences in the Fc region with candidate murine antibodies, SILu™MAb Mouse provides universal utility, and thus, eliminates the need to produce candidate-specific internal standards._x000D_ Physical form_x000D_ Each vial of SILu™MAb Mouse contains the labeled antibody lyophilized from a solution of phosphate buffered saline. Vial content was determined by measuring A280 and using an extinction coefficient (E0.1%) of 1.4._x000D_ Preparation Note_x000D_ Produced utilizing enriched media containing stable isotope labeled amino acids such as [13C6, 15N4]-Arginine and [13C6, 15N2]-Lysine. Expressed in CHO cells, SILuMAb Mouse is designed to be used as a universal internal standard for bioanalysis of monoclonal murine antibodies in animal pharmacokinetics (PK) studies_x000D_ Reconstitution_x000D_ SILu™MAb Mouse recovery is maximized when 0.1% formic acid is used for reconstitution of the lyophilized product._x000D_ Reconstitution with other solvents may reduce recovery. Do not freeze after reconstitution._x000D_ • Briefly centrifuge the vial at ~10,000 × g to collect the product at the bottom of the vial._x000D_ • Add 500 μL of ultrapure water containing 0.1% formic acid to the vial._x000D_ • Mix the contents by gently inverting the vial a minimum of 5 times._x000D_ • Allow the vial to stand at room temperature for at least 15 minutes and repeat mixing by inversion._x000D_ Legal Information_x000D_ SILu is a trademark of Sigma-Aldrich Co. LLC