The RayBio^® Rapid Histone Protein Extraction Kit provides a quick and efficient method for extracting histone-enriched proteins from cultured cells or tissue samples in approximately 2 hours. The protocol is designed to preserve histone post-translational modifications while producing histone-enriched extracts with relatively low background.

This kit is intended for applications where histone proteins are the primary target and a separate nuclear protein fraction is not required. For applications requiring sequential isolation of cytoplasmic, nuclear, and histone protein fractions, or for cleaner fractionation with retention of the nuclear protein fraction, we recommend using the RayBio® Cytoplasmic, Nuclear and Histone Protein Extraction Kit (Catalog #: CNH-50).

• Pre-Elution Buffer
• Histone Elution Buffer
• Histone Balance Buffer
• Protease Inhibitor Cocktail
• DTT

• Pipette tips (barrier tips recommended) and microcentrifuge tubes
• PBS
• Deionized (DI) Water
• Microcentrifuge
• Vortex mixer
• Precision pipettes to deliver 2 µL to 1 mL volumes
• Tissue homogenizer if using tissue samples (Dounce tissue grinder recommended)
• Refrigerated centrifuge with swing out rotor and refrigerated microcentrifuge
• Optional: PMSF (Phenylmethyl sulfonyl fluoride)

1. Prepare cell or tissue samples as instructed.
2. Prepare reagents according to the tables.
3. Treat the sample with Pre-Elution Buffer to release cytoplasmic and nuclear proteins. Collect supernatant as the Non-Histone Protein Extract if needed or discard it if only the histone fraction is required. If keeping this fraction, addition of Protease Inhibitor Cocktail and DTT is recommended.
4. Extract histone proteins from the remaining pellet using Histone Elution Buffer for 1 hour at 4°C.
5. Collect the Histone Extract, then add Histone Balance Buffer and Protease Inhibitor Cocktail. Add DTT if the extract will be stored long term. If you want to use Histone extract for ELISA kit, might avoid DTT or add less than DTT to 0.5 mM
6. Store extracts at –80°C until use.