This Cell Lysis Buffer is a ready-to-use Western blot related reagent solution used for efficient extraction of total soluble protein in nondenatured state from mammalian cells. Cell lysis can be finished in 30 minutes. The cell lysis buffer has been validated for use with COS-7, NIH3T3, Hepa 1-6, 293T, CHO and other cell types. It is able to lyse plated cells and pelleted cells from suspension mammalian cultures. The produced cell lysates are directly compatible with reporter gene expression assays (luciferase, beta-galactosidase, chloramphenicol acetyl transferase, CAT, alkaline phosphatase), protein kinase assays (PKA, PKC, tyrosine kinase), phosphatase assays (general phosphatases, tyrosine phosphatases), immunoassays (Western blots, ELISAs, RIAs, immunoprecipitation), Coomassie-Blue and silver staining, BCA protein assay, protein purification procedures, electrophoresis, and many other downstream applications.