Rabbit Monoclonal Antibody Development with QMAb™
Why Rabbit Monoclonal Antibody?
Rabbit antibodies typically exhibit higher affinity and specificity for antigens due to the greater diversity of their natural antibody repertoire. Consequently, rabbit monoclonal antibodies are known to display superior sensitivity in immuno-applications. Moreover, the diverse antibody repertoire of rabbits enables them to recognize epitopes that may not be detectable using other systems.
QMAb™ (Quick Monoclonal Antibody from Blood) is a platform technology that enables the cloning of antibody light and heavy chains coding DNA from B cells in peripheral blood. The cloned DNA sequences are expressed in mammalian cell expression systems to generate recombinant monoclonal antibodies. These antibodies have superior lot-to-lot consistency compared to those produced by hybridomas because they are derived from cloned DNA sequences and are not susceptible to cell-line drift or lot-to-lot variation.
How Does the QMAb™ Platform Work?
We are dedicated to simplifying the antibody development process for you by managing the complex aspects on our end. All you have to do is send us your antigen, and we will manage everything else, delivering your antibody clones. Get in touch with us to obtain your own set of antibodies.
How Does the QMAb™ Compare to Other Platforms?
| Area | QMAb™ | Other Single B/Memory Cell Technology | Rabbit Hybridoma Technology |
|---|---|---|---|
|
Source of B Cell |
Peripheral Blood |
Spleen or Lymph node
|
Spleen or Lymph node
|
|
Animal Life |
Rabbit kept alive for future studies |
Kill rabbit to get spleen
|
Kill rabbit to get spleen |
|
Suitable for Time Course Study |
Yes. Use blood samples from multiple time points. |
No. Only single time point allowed. |
No. Only single time point allowed. |
|
Specific Epitope Selection (e.g., anti-Idiotype) |
Yes |
No |
No |
|
Number of Clones |
High |
High
|
Low |
|
Clone Preservation |
DNA sequence, plasmid DNA |
DNA sequence, plasmid DNA
|
Hybridoma cell line
|
|
Loss of Material Risk |
None |
None |
High |
|
Development Time Line |
4 Months |
5 Months |
> 6 Months |
Case Study #1
Rabbit Monoclonal Antibodies for HCV Core Antigen
Hepatitis C Virus (HCV) is a significant global health concern, with approximately 3% of the world’s population affected by the infection. In the United States alone, over 2 million people currently have HCV. About 80% of HCV-infected individuals develop chronic hepatitis, with many of them progressing to cirrhosis and hepatocellular carcinoma (HCC). The HCV core antigen is a non-glycosylated nucleic acid-binding nucleocapsid protein (C) consisting of approximately 190 amino acids (about 21 kD). Studies have demonstrated that core antigen levels show a significant correlation with HCV-RNA assay results, and have been proposed as a potential marker for viral replication. Antibodies against HCV core antigen are utilized to develop highly sensitive immunoassays for detecting HCV infection.
| Clone ID | Kd (M) |
|---|---|
| HCV-2 | 5.01E-12 |
| HCV-3 | 1.04E-11 |
| HCV-4 | 3.37E-11 |
| HCV-5 | 1.75E-11 |
| HCV-6 | 1.34E-11 |
| HCV-8 | 1.10E-11 |
| HCV-10 | 9.63E-12 |
| HCV-11 | 9.31E-12 |
| HCV-16 | 7.97E-12 |
| HCV-18 | 7.91E-12 |
| HCV-25 | 1.52E-11 |
| HCV-27 | 8.54E-12 |
| HCV-35 | 6.15E-12 |
| HCV-41 | 6.65E-12 |
| HCV-42 | 7.13E-12 |
| HCV-11A | 8.79E-12 |
| HCV-12 | 6.23E-12 |
| HCV-42 | 5.91E-12 |
Case Study #2
Antibodies for SARS-COV-2 Nucleocapsid Protein
COVID-19 is an infectious disease caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), a highly transmissible type of coronavirus that primarily spreads through respiratory droplets. Among the viral components, the N protein (nucleocapsid protein) is critical in the virus’s life cycle. This protein is responsible for encapsulating the viral RNA genome and plays a crucial role in viral replication, transcription, and packaging. The detection of N protein using immunoassays is widely used for the detection of active viral infection during the pandemic, and the antibodies to N protein are essential for sensitive rapid tests for COVID-19.
Using the QMab™ platform, we generated 15 rabbit monoclonal antibodies against the N protein. These antibodies exhibit a remarkable degree of specificity and possess high affinity, with Kd values ranging from 17 pM to 37 pM. Notably, one of the clones (highlighted in red) can distinguish between SARS-CoV and SARS-CoV-2 despite a protein sequence homology exceeding 95%.
Case Study #3:
Antibodies for SARS-COV-2 Spike Protein
The spike protein of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is a protein that plays a crucial role in viral entry and infectivity. It is a transmembrane glycoprotein that protrudes from the surface of the virus and binds to the host receptor, angiotensin-converting enzyme 2 (ACE2), on the surface of human cells. The binding of the spike protein to ACE2 initiates the viral entry process, allowing the virus to infect human cells and cause COVID-19. The spike protein has been extensively studied and is the primary target for most COVID-19 vaccines and therapeutic antibodies. Specifically, the S1 domain that contains the receptor-binding domain (RBD) is a critical target for antibodies.
We utilized the QMAb™ platform to isolate 29 rabbit monoclonal antibodies that target the S1 protein. These antibodies exhibit specificity for unique epitopes on the S1 protein, and two of them have a specific binding affinity for the RBD domain.
The following are the affinity data and the epitope mapping to the above 4 regions of the S protein. These highly specific clones are obtained from using the QMAb™ platform.
| Clone ID | Kd EC50 | Binding Epitope |
|---|---|---|
| HQ373_40A | 4.09E-12 | AA 514 - 680 |
| HQ373_19A | 4.31E-12 | not determined |
| HQ373_7A | 4.36E-12 | not determined |
| HQ373_4A | 4.66E-12 | AA 514 - 680 |
| HQ373_31A | 4.85E-12 | AA 514 - 680 |
| HQ375_29B | 4.88E-12 | AA 191-364 |
| HQ375_82B | 6.23E-12 | AA 364 - 514 (RBD containing) |
| HQ373_28A | 6.90E-12 | AA 514 - 680 |
| HQ375_27B | 7.30E-12 | AA 1 - 191 |
| HQ375_81B | 7.58E-12 | AA 514 - 680 |
| HQ373_26A | 7.65E-12 | AA 191-364 |
| HQ373_46A | 7.88E-12 | AA 514 - 680 |
| HQ373_14A | 8.61E-12 | AA 514 - 680 |
| HQ373_33A | 9.07E-12 | AA 364 - 514 (RBD containing) |
| HQ373_25A | 9.26E-12 | AA 191-364 |
| HQ375_72B | 9.43E-12 | not determined |
| HQ375_48B | 9.64E-12 | AA 1 - 191 |
| HQ375_67B | 1.12E-11 | AA 514 - 680 |
| HQ375_85B | 1.42E-11 | AA 514 - 680 |
| HQ375_86B | 1.46E-11 | AA 514 - 680 |
| HQ375_30B | 3.10E-11 | AA 514 - 680 |
| HQ375_35B | 3.24E-11 | not determined |
| HQ373_29A | 3.54E-11 | AA 514 - 680 |
| HQ373_42A | 3.66E-11 | AA 191-364 |
| HQ373_36A | 8.01E-11 | AA 191-364 |
| HQ373_16 | 3.24E-11 | AA 514 - 680 |
| HQ373_18 | 1.61E-11 | AA 514 - 680 |
| HQ373_40 | 1.66E-11 | AA 514 - 680 |
| HQ373_53 | 1.26E-11 | AA 514 - 680 |
Case Study #4
Antibodies for Guinea Pig Cytokines
Guinea pigs have served as experimental animals due to their biological similarities to humans. Their use has extended to various fields of biomedical research, such as nutritional, vaccine, and hormonal studies, as well as investigations of the auditory system and infectious diseases. However, the limited availability of immunological reagents has hindered the usefulness of guinea pigs as a small animal model for biomedical research, particularly for immunological analysis. Thus, the development of affinity reagents for the immune system of guinea pigs is crucial to enable the effective use of this animal model in immunological analysis.
Sponsored by NIAID, we have utilized the QMAb™ platform to create rabbit monoclonal antibodies for guinea pig cytokines and CD markers. These antibodies are now accessible to researchers through our store.
| Cytokine | IL-2 | IL-17 | IL-6 | IL-10 | IL-12 p40 | IL-12 p35 | IL-13 | TNFa | IL-8 | MCP1 | IL1B |
|---|---|---|---|---|---|---|---|---|---|---|---|
|
Number of Specific Clones |
8 |
7 |
8 |
6 |
6 |
6 |
5 |
7 |
3 |
7 |
4 |
Functional assay results of sample clones:
| Target | Antidoby Clone ID | Western Blot | ELISA | ELISpot |
|---|---|---|---|---|
|
IL-2 |
GP1-1 |
Yes |
Yes. Pair with GP1-8 |
Yes |
|
GP1-2 |
Yes |
No |
Not Tested |
|
|
GP1-8 |
Yes |
Yes. Pair with GP1-1 |
yes |
|
|
IL-17 |
GP3-10 |
Yes |
Yes. Pair with GP3-17 |
Yes |
|
GP3-17 |
Yes |
Yes. Pair with GP3-10 |
Yes |
|
|
GP3-19 |
Yes |
No |
Not Tested |
|
|
IL-6 |
GP4-27 |
Yes |
Yes. Pair with GP4-32 |
Yes |
|
GP4-32 |
Yes |
Yes. Pair with GP4-27 |
Yes |
|
|
GP4-33 |
Yes |
No |
Not Tested |
|
|
IL-10 |
GP5-39 |
No |
Yes. Pair with GP5-40 or GP5-41 |
Yes |
|
GP5-40 |
Yes |
Yes. Pair with GP5-39 |
Not Tested |
|
|
GP5-41 |
Yes |
Yes. Pair with GP5-39 |
Yes |
Case Study #5:
Antibodies for Antibody-Drug Development
Developing therapeutic antibody drugs requires highly specific and sensitive anti-idiotype antibodies to conduct reliable pharmacokinetic and immunogenicity assays. The QMAb™ platform is an excellent tool for discovering antibodies that target specific epitopes, and our team has significant expertise in generating anti-idiotype antibodies using integrated epitope-specific screening and differential screening strategies. The resulting monoclonal antibodies have demonstrated high specificity and do not cross-react with human IgG, enabling accurate and reliable PK assays, even in the presence of a vast excess of human antibodies in human serum.
We have utilized the QMAb™ platform to assist our clients in developing the following anti-ID antibodies:
Antibody idiotope and paratope overlap. As a result, the anti-ID antibody competes with the target antigen for the same binding site. These antibodies are often used for measuring the concentration of free antibody drugs.
Monoclonal antibodies with non-neutralizing and non-antigen blocking properties
Idiotope and paratope do not overlap. These antibodies bind to the antibody drug outside of its antigen binding site, and are utilized for the detection and quantification of the total antibody drug.
Monoclonal antibodies that are complex-specific
Bind exclusively to the antibody-drug antigen complex. This specificity makes them valuable tools for quantifying antigen-bound antibody drug.
By keeping the animals alive, the QMAb™ platform allows for the continued production of polyclonal anti-drug antibodies (ADA) alongside monoclonal development, which can be utilized in immunogenicity assays.
Other Cases
Using QMAb™ to Discover Monoclonal Antibodies
- FITC – Small Molecule Antigen (MW 389)
- Hepatitis B Virus Core Antigen – Peptide Antigen
- Streptavidin – Protein Antigen
- Group A Streptococcus – Polysaccharide Antigen
- Others – numerous projects for clients, not disclosed
Beyond Rabbit ---
QMAb™ Is Suitable For Other Species Too
The QMAb™ platform can be used to discover superior monoclonal antibodies from other species. We have use it successfully with the following host species:
- chicken
- llama
The Next QMAb™ Success Story Could be Yours ...
Empower your research with QMAb™ – make high quality antibodies to advance your research. Contact us now to get started.
Antibody Production and Engineering
Antibody Production
In addition to our QMAb™ antibody cloning platform, we have developed a proprietary method for generating recombinant antibodies in mammalian cells with exceptional efficiency. Our ISO17025 accredited facility is capable of routinely producing high-quality antibodies with consistent results, ranging from several hundred micrograms to grams in scale.
Qoolabs offers recombinant antibody production services that leverage expert knowledge and optimized processes to deliver quality and speed. The features of our service include:
- High Quality: In addition to standard procedures, we collaborate with clients to conduct rigorous custom testing and multi-validation studies that safeguard the quality of the product.
- Scalability: Our robust internal processes ensure stable scaling up of the manufacturing process.
- Consistency: Our ISO17025 accredited facility minimizes lot-to-lot variability, ensuring a reliable product with each production run.
Other Engineering and Production Services
- Stable cell line generation
- Antibody affinity maturation
- Antibody humanization