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AAT Bioquest

What are the different types of blocking buffers?

Posted May 2, 2024


Answer

Types of blocking buffers:

  • Normal serum: Normal serum is a common component in blocking buffers. This is because the antibodies present in serum bind to reactive sites, preventing nonspecific binding of secondary antibodies in the assay. Using serum from a source species for the secondary antibody is important. Serum is typically used at concentrations of 1% - 5% (w/v).
  • Protein solutions: Apart from serum, blocking buffers often contain proteins such as gelatin, bovine serum albumin (BSA), or nonfat dry milk. When added, either alone or in combination, at final concentrations of 1% - 5% (w/v), they complete for binding to nonspecific sites in the sample.
  • Pre-formulated commercial buffers: Ready-made commercial blocking buffers typically contain proprietary protein-free compounds or highly purified single proteins. Using commercial blockers offers benefits such as improved performance compared and longer shelf lives.
Additional resources

Primary Antibody Selection and Blocking Techniques for Immunohistochemistry

Comparison of blocking buffers for western blotting.

Immunohistochemistry (IHC)

Stayright™ Purple HRP Staining Kit