ELISA

Specialized ELISA buffers and substrates

Bio-Rad has a comprehensive range of buffers and substrates for optimizing ELISAs. Our products are manufactured to ISO 9001 standards ensuring reliability and consistency in performance. Whether you need to stabilize coated proteins, block non-specific binding, reduce matrix effects or improve signal to noise ratio, we have the finest reagents for you. Backed by a 100% Satisfaction Guarantee, this ensures if you are not satisfied with any Bio-Rad product we’ll do everything we can to make it right.


Coating Buffers

When the capture antibody or antigen is bound to a suitable surface, coating buffers should be used to stabilize coated proteins. Increasing adsorption to the plate improves ELISAs.

ELISA Coating Buffer (BUF030)

A specialist coating buffer designed for sandwich ELISAs to stabilize the coating protein and maximize adsorption. Gives greater binding reactivity with the detection molecule and enhanced signal.

AbGuard® Plate Stabilizer (BUF063)

Simultaneously stabilizes and preserves microwell plates coated with proteins or other biomolecules and blocks any free binding sites. It preserves the biological activity of bound molecules and prevents degradation, denaturation and leaching. It also blocks free binding sites without creating any interference.


Blocking Buffers

Blocking is a critical step for ELISAs and there are a number of options available. Choosing the right blocking buffer increases sensitivity by reducing non-specific binding and background noise.

Block Ace (BUF029)

Superior to 1% BSA, Block Ace is a high-performance blocking buffer which can also be used as a wash buffer, and for diluting antibodies. In comparison to BSA, Block Ace provides reduced backgrounds and sharper standard curves.

BSA Block (BUF032)

Minimize non-specific binding in sandwich and antigen-down ELISAs using BSA Block. Based on BSA, this buffer has a proprietary protein stabilizer that creates a long-term stable environment for coating antigens or capture antibodies.

Ultrablock (BUF033)

A buffer containing proprietary non-mammalian proteins from fish designed to reduce non-specific binding. With extra blocking strength, it is suitable for use in antigen-down and sandwich ELISAs with high background and when working with human, bovine and porcine serum samples. Ultrablock can coat non-specific binding sites that are sterically inaccessible to traditional blockers.

Synblock (BUF034)

For maximum blocking strength use Synblock, a novel non-protein blocking formulation for antibody-coated and sandwich ELISAs. This synthetic, inert blocking agent provides maximum reduction of interference and eliminates non-specific background noise.


Assay Diluents

Reduce matrix effects by using assay diluents to equalize differences between the sample matrix (serum, plasma or urine) and the standard curve. Assay diluents can be pipetted directly onto the plate prior to adding samples, minimizing variation among samples and lowering background noise.

General Assay Diluent (BUF037)

This product is suitable for most sandwich ELISAs and formulated for use with serum and plasma samples. It contains goat sera to reduce non-specific interactions and a proprietary calcium chelating agent to inhibit interference from thrombin and complement.

IgM Reducing Assay Diluent (BUF038)

BUF038 is formulated for use with problematic serum and plasma samples in sandwich ELISA, with proprietary additives to reduce IgM-mediated conjugate bridging interference which can cause substantial background noise. This diluent also contains proteins from goat sera to reduce non-specific interactions and a proprietary calcium chelating agent to inhibit interference from complement and thrombin.

Neptune Assay Diluent (BUF039)

This diluent does not contain any immunoglobulin-based components that could interfere with the signal but does contain a non-mammalian protein base designed to minimize non-specific binding of serum and plasma samples from human, porcine or bovine source. It also contains specially selected detergents to enhance the signal.

HISPEC Assay Diluent (BUF049)

BUF049 works to reduce cross-reactivity, non-specific binding and matrix effects in immunoassays such as ELISA, EIA, Western blotting, immuno-PCR, protein arrays, multi-analyte immunoassays and immunohistochemistry. This buffer can be used when minimizing human anti-mouse antibody (HAMA) or Rheumatoid Factor reactivity in immunoassay applications. HISPEC buffer can efficiently deal with many interferences including those caused by HAMA, and therefore can substitute for HAMA blockers.


Conjugate Stabilizers & Diluents

Conjugate stabilizing diluents can be used to reconstitute lyophilized conjugates and to dilute concentrated conjugate. Using stabilizing diluents prolongs the shelf-life of newly conjugated proteins which can be unstable and lose activity after rehydration.

AbGuard® HRP Stabilizer Plus (BUF052)

This product gives superior stabilization of HRP-conjugated proteins in dilution and allows manufacturers of diagnostic assays to provide pre-diluted ready-to-use enzyme conjugates. This diluent does not contain BSA or any other bovine materials but does contain weak concentrations of rabbit antibodies.

AbGuard® AP Stabilizer (BUF053)

Provides superior stabilization of AP-conjugated proteins with a similar specification to our HRP stabilizing product above.


Washing Buffers

Rinsing with wash buffers during the coating process and between reagent addition steps effectively removes excess material from the wells, without disrupting the binding reaction.

Wash Buffer (BUF031)

This high-performance washing solution increases the efficiency of washing stages leading to a reduction in background noise and increased signal. This buffer is compatible with Avidin, Alkaline Phosphatase and HRP.

Block Ace (BUF029)

Superior to 1% BSA, Block Ace is a high-performance blocking buffer which can also be used as a wash buffer, and for diluting antibodies. In comparison to BSA, Block Ace provides reduced backgrounds and sharper standard curves.


Substrates

Chemical substrates are converted by enzymes to produce a detectable signal, i.e. color change or fluorescent emission.

TMB Core+ (BUF062)

A high-performance TMB (3,3´,5,5´- tetramethylbenzidine) solution, recommended for use in ELISAs as a substrate for Horseradish Peroxidase (HRP). TMB Core+ contains TMB, substrate buffer and hydrogen peroxide and has been optimized for increased sensitivity, minimal background and rapid development. It produces a deep blue color read at 655 nm. The reaction may be stopped with sulfuric acid, resulting in a yellow color read at 450 nm.

TMB Sensitive (BUF066)

Offers greater sensitivity than other TMB reagents offered by Bio-Rad. Also available in a prestained version (BUF067)

TMB CORE (BUF056)

A high performance TMB (3,3´,5,5´- tetramethylbenzidine) solution recommended for use as a substrate for horseradish peroxidase. Contains TMB, substrate buffer and hydrogen peroxide in a safe, ready to use solution. Also avaible in a prestained version (BUF057)

TMB SIGNAL+ (BUF054)

A high performance TMB (3,3´,5,5´- tetramethylbenzidine) solution recommended for use as a substrate for horseradish peroxidase. TMB SIGNAL+ has been optimized to enable increased sensitivity and enhanced stability. It also provides minimal background and rapid development times. TMB SIGNAL+ is also available in a prestained version (BUF055)

Note: The red indicator found in the prestained TMB substrates will disappear after addition of the stop solution. Therefore it will not interfere in end-point or kinetic assays, and will not affect the stability of the substrate.

pNPP (BUF044)

This high-performance p-NitroPhenyl Phospahte (pNPP) solution, is ready-to-use and recommended for ELISAs as a substrate for Alkaline Phosphatase for kinetic and endpoint tests.


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