5X Lysis Buffer 4 is specially formulated for use with select Phospho and Total THUNDER™ Cell Signaling Assay Kits. This buffer is already provided in these kits, but can be ordered separately. The Lysis Buffer 4 must be supplemented with the THUNDER™ Phosphatase Inhibitor Cocktail (100X; not included) to ensure protection of proteins from dephosphorylation.