Imject™ Maleimide-Activated Ovalbumin
Imject™ Maleimide-Activated Ovalbumin
Thermo Scientific™

Imject™ Maleimide-Activated Ovalbumin

Thermo Scientific Imject Maleimide-Activated Ovalbumin is sulfhydryl-reactive ovalbumin (OVA) for hapten-carrier conjugation with cysteine-containing peptides and other thiolated antigens.Features ofRead more
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Catalog NumberQuantity
771262 mg
771255 x 2 mg
Catalog number 77126
Price (USD)
174.00
Each
Add to cart
Quantity:
2 mg
Price (USD)
174.00
Each
Add to cart
Thermo Scientific Imject Maleimide-Activated Ovalbumin is sulfhydryl-reactive ovalbumin (OVA) for hapten-carrier conjugation with cysteine-containing peptides and other thiolated antigens.

Features of Imject Maleimide-Activated Ovalbumin:

• Maleimide-Activated Ovalbumin, supplied lyophilized in PBS (pH 7.2) with stabilizer
• Activated with 5 to 15 moles of maleimide per mole of ovalbumin
• Ideal for conjugating cysteine-containing peptide antigens to make immunogen or screening target
• Conjugation reaction complete in 2 hours; results in stable, covalent thioether bonds
• Single polypeptide protein with molecular mass of 45,000 Daltons
• Contains 14 aspartic acid and 33 glutamic acid residues whose carboxyl groups account for the net negative charge (pI 4.63) of OVA
• Not as immunogenic as keyhole limpet hemocyanin (KLH) but more soluble in DMSO (dimethyl sulfoxide) for applications that require this solvent
• Useful as an irrelevant protein carrier for antibody screening and immunoassays after using KLH as the carrier protein to generate the immune response against the hapten

This product consists of purified, carrier-grade ovalbumin that has been modified with SMCC crosslinker to attach maleimide groups capable of forming covalent crosslinks with sulfhydryl (-SH) moieties on cysteine residues of peptides and other molecules. Immunogens are easily prepared from peptide antigens that have been engineered with a terminal cysteine residue as a precise conjugation point. Several antigen molecules can be attached per carrier protein molecule without blocking intended epitopes by crosslinking to primary amines or carboxylates within the peptide sequence.

Carrier proteins are large, complex molecules capable of stimulating an immune response upon injection. Successful production of antibodies specific to small antigens (i.e., peptides or drug compounds) requires that these haptens be covalently conjugated to a larger, more complex molecule (usually a protein) to make them immunogenic. Carrier proteins are chosen based on immunogenicity, solubility, and whether adequate conjugation with the carrier can be achieved.

Ovalbumin (OVA), the most abundant protein in chicken egg whites, is a convenient protein for a variety of uses in the laboratory. The 45kDa protein is sufficiently large and complex to be mildly immunogenic. Consequently, OVA can be used as a carrier protein for conjugation to haptens and other antigens to make them more immunogenic for immunization. If not commonly used to prepare the primary immunogen, OVA is a popular carrier protein to make antigens more amenable to analysis (e.g., screening assays involving plate coating) of antibodies that were produced using KLH or other more immunogenic carrier protein.

Imject Ovalbumin is not as immunogenic as other proteins, such as keyhole limpet hemocyanin (KLH). However, OVA's independent structure make it especially useful as a carrier for peptides and other small antigens that by themselves are difficult to manipulate in typical screening assays such as ELISA. Although it is more hydrophobic and less soluble in aqueous buffers than BSA, ovalbumin remains soluble in up to 70% DMSO, making it useful for conjugation with haptens that require DMSO for solubility. Ovalbumin contains numerous primary amines, some of which have been modified to make Maleimide-Activated Ovalbumin.

Related Products
Imject™ Ovalbumin (in PBS)
For Research Use Only. Not for use in diagnostic procedures.
Specifications
Quantity2 mg
Product LineImject™
Unit SizeEach
Contents & Storage
Upon receipt store product at 4°C. Product is shipped at ambient temperature.

Frequently asked questions (FAQs)

What do I need to consider when designing a peptide for antibody production?

We recommend that hydrophobic residues comprise 50% or less of all the residues in your sequence. Make sure there is at least one charged residue for every five amino acids: this is generally known to enhance the solubility of the peptide. Peptides (compared to polypeptides, which fold and bury the hydrophobic amino acids) are too small to fold, so just a few hydrophobic amino acids may leave them insoluble.

Other guidelines include:
Peptides containing multiple Cys, Met, and Trp can be hard to synthesize.
Some sequences are problematic in solid-phase peptide synthesis or cleavage and are best avoided; these include Asp-Pro sequences or stretches of amino acids that require bulky protecting groups on their side chains during synthesis.
Glycine is often good for antigenicity as it has only a hydrogen side chain; this allows for complete rotation.
Please note that we offer a Custom Antibody Production service (https://www.thermofisher.com/us/en/home/life-science/antibodies/custom-antibodies/custom-antibody-production.html) that includes the use of our proprietary Antigen Profiler and Antigen Preparation tool (https://www.thermofisher.com/us/en/home/life-science/antibodies/custom-antibodies/custom-antibody-production/antigen-profiler-antigen-preparation.html).

What is the optimal peptide length for antibody production?

Most peptide antigens range in length from 12 to 16 residues and are relatively easy to synthesize. Peptides of 9 residues or shorter have been effective antigens for antibody production, but peptides longer than 16 amino acids may contain several epitopes and form secondary structures. Peptides in excess of 18 residues begin to present more synthetic challenges. Before you synthesize your peptide, we recommend doing a BLASTP search using your peptide sequence. This is to make sure that the peptide is not homologous or identical to a sequence in a completely unrelated protein in the host animal.

Please note that we offer a Custom Antibody Production service (https://www.thermofisher.com/us/en/home/life-science/antibodies/custom-antibodies/custom-antibody-production.html) that includes the use of our proprietary Antigen Profiler and Antigen Preparation tool (https://www.thermofisher.com/us/en/home/life-science/antibodies/custom-antibodies/custom-antibody-production/antigen-profiler-antigen-preparation.html).

What happens if antibodies are stored improperly?

Improper storage of antibodies can lead to:
- Degradation: Loss of activity and specificity
- Aggregation: Formation of precipitates or clumps
- Reduced performance: Poor results in assays or experiments

Find additional tips, troubleshooting help, and resources within our Antibodies and Immunoassays Support Center.

What do antibody pair kits contain, how many samples can I process, and how can I find a list of antibody pair kits by target?

Antibody pair kits contain capture antibody, detection antibody, recombinant standard and HRP conjugate. Each contains enough reagents to process forty 96-well plates. A list of Antibody Pair Kits (https://www.thermofisher.com/us/en/home/life-science/protein-biology/protein-assays-analysis/elisa/antibody-pair-kits.html) is available by target.

Find additional tips, troubleshooting help, and resources within our Antibodies and Immunoassays Support Center.

What do Reagent Sets contain, how many samples can I process, and how can I check if a Reagent Set is available for my target?

Reagent Sets contain Capture Antibody, Detection Antibody, Recombinant Standard, HRP Conjugate, TMB Substrate and Stop Solution. Each contains enough reagents to process five 96-well plates. Reagent Sets are included in the main list of ELISA (https://www.thermofisher.com/us/en/home/life-science/protein-biology/protein-assays-analysis/elisa/antibody-pair-kits.html) kits (search by “Reagent Set”).

Find additional tips, troubleshooting help, and resources within our Antibodies and Immunoassays Support Center.