Blocking Buffers

Efficiently reduce nonspecific binding and stabilize your coated protein.

Once the antibody or protein antigens have been properly adsorbed onto the plate (we recommend CB1 Antibody Coating Buffer or CB2 Antigen Coating Buffer), the next critical step in creating a reliable assay is the blocking of the plate.

Blocking is done to protect the coated protein from harsh external conditions while masking any uncoated regions on the plate. As the blocking process has a profound effect on both the specific and nonspecific signals generated in the assay, the proper selection of block buffer is a key element in the preparation of a functional ELISA. The proper block buffer can increase sensitivity, reduce nonspecific binding, and lengthen the shelf-life of the coated plate.

Because ELISAs may be configured in several ways, each with unique blocking requirements, ICT has created 4 proprietary block buffer formulations for use with sandwich and antigen-down ELISAs:

General Blocker (BB1)

Based on mammalian proteins from BSA. Use this blocker for: Sandwich and antigen-down ELISAs requiring low to average blocking strength.

General Blocker (BB1)

Neptune Block (BB2)

Based on nonmammalian proteins from fish, for extra blocking strength. Use this blocker for: Antigen-down ELISAs. Sandwich ELISAs with high backgrounds. ELISAs testing human and other mammalian samples.

Neptune Block (BB2)

SynBlock (BB3)

Based on small synthetic blocking molecules, for ELISAs that require extra blocking strength. Use this blocker for: Sandwich ELISAs requiring extra blocking. Antigen-down ELISAs requiring extra blocking. ELISAs with high nonspecific binding of enzyme-labeled conjugates.

SynBlock (BB3)

Phosph-Free Blocker (BB4)

Phosphate-free, based on small synthetic blocking molecules, for ELISAs using alkaline phosphatase detection, and for those assays with super sensitivity requirements. Use this blocker for: ELISAs using alkaline phosphatase. ELISAs based on chemically-treated or glass plates. ELISAs used with a microfluidics system.

Phosph-Free (BB4)

Optimization Pack (BBOP)

Includes one bottle of our first three block buffers (BB1, BB2, and BB3; 100 mL each). We will always give you our best advice regarding which block buffer to try, but it is sometimes best to just try each one with your assay.

Block Buffer Optimization Pack (BBOP)

Plate Coating Buffers  Conjugate Stabilizer Diluents  Sample Diluents 

Assay Diluents  Wash Buffer  Phosphate Buffered Saline 

Substrates  Stop Solutions  Custom Lab Solutions

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ICT has specifically formulated several blocking buffers for use with sandwich and antigen-down ELISAs. All blocking buffer formulations contain stabilizing components to stabilize the coated protein, allowing for greater binding reactivity with the detection molecule.