U-937 cells were grown in RPMI-1640 medium supplemented with 10% fetal bovine serum. Cells were washed with PBS and then incubated on ice in modified RIPA buffer, containing 150 mM sodium chloride, 50 mM Tris HCl, pH 7.4, 1 mM EDTA, 1.0% NP-40, 0.5% sodium deoxycholic acid , 0.1% SDS and 0.01% (w/v) sodium azide to lyse the cells. Protein integrity was ensured using a cocktail of protease inhibitors with broad specificity for the inhibition of aspartic, cysteine, and serine proteases as well as aminopeptidases (0.1 mM AEBSF HCl, 0.08 μM Aprotinin, 5 μM Bestatin, 1.5 μM E-64, 2 μM Leupeptin Hemisulfate, 1 μM Pepstatin A). Phosphatase inhibitors 1 mM NaF and 1 mM Na3VO4 were also added. Cell debris was removed by centrifugation. Protein concentration was determined by a modified Lowry assay using a commercially available kit. Protein concentration was adjusted to 4 mg/ml with 1X RIPA buffer.
Size
500 μg
Concentration
4.0 mg/ml
Applications
Chip, Immunoprecipitation, Western Blot. Multi-purpose U-937 Whole Cell Lysate are especially prepared as positive control for multiple assays including western blot, immunoprecipitation (IP), capture ELISA or other assays requiring native protein sample. For separation by SDS-PAGE and subsequent western blot analysis, lysates should be diluted by user to desired concentration in SDS-PAGE buffer with 2-mercaptoethanol or dithiothreitol as the reducing agent and heated to 95° C for 5 minutes. Sample is ready for use in immunoprecipitation and ELISA experiments, conditions should be optimized by the user. Rockland recommends its Trueblot IP reagents for immunoprecipitation experiments.