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ChonBlock: Buffers for Immunoassay

Chondrex, Inc. has released ChonBlock a blocking and sample dilution buffer which offers substantial reduction of background interference and is more cost effective than other proprietary blocking buffers

ELISA Buffer

ELISA is a convenient and sensitive method for assaying antibodies and antigens, and is widely utilized in many fields.  However, false positive reactions are often erroneously interpreted as real antibody-antigen reactions, and the resulting conclusions have misled the research and clinical fields.

In order to improve the antibody assay method in ELISA, Chondrex, Inc. provides ChonBlock: a buffer that can be used for blocking (Figure 1) and sample dilution (Figure 2).  ChonBlock is especially useful for assaying autoantibodies in human and animal sera at low dilutions where the likelihood of false positive reactions is great, as well as anti-environmental factor antibodies which are often underestimated due to interference caused by buffer components.

Western Blot Buffer

Traditional buffers based on BSA, casein, and NGS have been used in western blot studies, but many results show high background and false positives, leading to misconstrued conclusions.  Furthermore, several western blot buffers are commercially available but they still have problems improving the signal to background noise (S/N) ratio in a western blot. Chondrex, Inc. provides ChonBlock buffers re-optimized for western blot, resulting in a higher S/N ratio than other buffers.  These new buffers allow high concentrations of primary antibody and secondary antibodies to increase assay sensitivity without high background.

ChonBlock ELISA Buffers

Product Catalog # Price (USD)
ChonBlock Blocking/Sample Dilution ELISA Buffer 9068 50.00
ChonBlock Detection Antibody Dilution Buffer 90681 50.00

ChonBlock Western Blot Buffers

Product Catalog # Price (USD)
ChonBlock Western Blot Buffer 1 (PBS) 9069P 99.00
ChonBlock Western Blot Buffer 1 (TBS) 9069T 99.00
ChonBlock Western Blot Buffer 2 for Goat (PBS) 90691P 49.00
ChonBlock Western Blot Buffer 2 for Goat (TBS) 90691T 49.00
ChonBlock Western Blot Buffer 2 for Rabbit (PBS) 90692P 49.00
ChonBlock Western Blot Buffer 2 for Rabbit (TBS) 90692T 49.00

 


Figure 1.  Prevention of false positive reactions.
Human serum samples diluted 1:100 with 5% BSA-Tween, NGS and ChonBlock were added to antigen non-coated, human type I collagen (HI), and human type II collagen (HII) coated wells.  BSA is not capable of blocking the hydrophobic binding of immunoglobulin components in sample specimens onto plastic surfaces, therefore almost identical OD values were observed in all wells regardless of ELISA plate coating.  In contrast, ChonBlock prevents this type of non-specific reaction and clearly distinguishes the true antibody-antigen reactions from false positive reactions as effectively as NGS.


Figure 2.  Accurate measurement of anti-environmental factor antibodies.
Human serum was serially diluted with NGS and ChonBlock, and assayed for anti-E. coli antibodies.  NGS which contains antibodies against virtually all potential environmental factors apparently inhibits the anti-E. coli antibodies in human serum by competitive binding.  In contrast, ChonBlock, which does not interfere with antibodies and antigens, allows for an accurate assay of the true antibody titer in human serum.