BSA Standard Solution (5 mg/mL)

Protein extraction uses physical, chemical or biological methods, such as ultrasonic disruption, salting out, cell lysis, electrophoresis, etc., to destroy the cell membrane structure and to separate the proteins from different components according to their characteristics.

Gel electrophoresis is a method for separating biological macromolecules (such as nucleic acids or proteins) by forcing them through a gel matrix under an electric field.

Protein electrophoresis separates proteins in a polyacrylamide gel under an electric field; in SDS-PAGE, sodium dodecyl sulfate denatures proteins and gives them a broadly similar negative charge-to-mass ratio, so migration mainly reflects apparent molecular mass through the gel matrix. The readout is a stained protein band pattern: band position estimates apparent molecular mass using protein standards, band intensity reflects relative protein abundance within the linear range of staining/detection, and changes in band pattern can reflect protein expression, degradation, purification, or sample composition.