Western Blot Separates Proteins Based on Size and Charge
Western blot is the laboratory technique that separates proteins based on their size and charge. This technique uses sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) to accomplish protein separation before detection 1, 2.
How Western Blot Works
The Western blot technique operates through three fundamental steps 1:
- Separation by size and charge: Proteins are first separated using gel electrophoresis, where they migrate through a polyacrylamide gel based on their molecular weight and charge 2, 3
- Transfer to solid support: The separated proteins are then electrophoretically transferred to a membrane (typically PVDF or nitrocellulose) 2, 4
- Detection: The target protein is identified using specific primary and secondary antibodies 1, 5
Why the Other Options Are Incorrect
PCR (Polymerase Chain Reaction) amplifies DNA sequences, not proteins, making it irrelevant for protein separation 1.
Flow cytometry detects particles and cells but does not separate proteins based on size and charge in the same manner as Western blot 6. While flow cytometry can analyze protein markers on cells or particles, it is fundamentally a detection method rather than a protein separation technique 6.
ELISA (Enzyme-Linked Immunosorbent Assay) detects and quantifies proteins through antibody binding but does not separate proteins by size and charge 6. ELISA is an immunological detection method, not a separation technique 6.
Clinical Context
Western blot is routinely used in biochemical characterization studies, particularly for analyzing protein composition 6. The technique requires careful attention to lysate preparation and antibody specifics for reproducible results 6. It remains a powerful staple in scientific research for detecting specific proteins from complex mixtures 3, 5.