In recent years, antibody drug development has continued to evolve towards greater complexity and precision. Next-generation biopharmaceuticals, represented by monoclonal antibodies, bispecific antibodies, Fc fusion proteins, and long-acting antibodies, are constantly driving the rapid upgrading of antibody engineering technology. Among these advancements, structural optimization of the Fc region has become a crucial technical pathway for improving drug stability, prolonging half-life, and regulating effector function.
In the Human IgG Fc region, the CH3 domain is not only a key region for maintaining the spatial structural stability of the antibody but also participates in the FcRn (neonatal Fc receptor)-mediated antibody recycling process, significantly influencing antibody metabolism and half-life in vivo. Therefore, the CH3 domain has become a major focus in current Fc engineering.
With the widespread application of Fc mutation strategies such as KIH (Knobs-into-Holes), LALA, and YTE in the development of bispecific and long-acting antibodies, traditional secondary antibodies have gradually revealed significant limitations in detection processes:
● Decreased ability to recognize Fc mutants
● Susceptibility to structural modifications leading to detection failure
● High nonspecific background
● Insufficient batch stability
● Difficulty in meeting the high consistency requirements of drug development stages.
Especially in antibody drug development, quality control, and functional analysis, the specificity and stability of detection tools directly affect the accuracy and reproducibility of experimental results. Achieving accurate detection of Fc-engineered antibodies has become a significant challenge in the field of antibody analysis.
To address this industry need, AlpVHHs based on its mature nanobody (VHH antibody) platform, has officially launched a new product: Anti-Human IgG (CH3 Fragment specific), AlpSdAbs® VHH series. This series of recombinant nanobodies specifically recognizes the CH3 domain of Human IgG, is compatible with various Fc engineered modifications, and effectively solves the recognition limitations of traditional secondary antibodies in the detection of Fc mutant antibodies. It provides a more accurate, stable, and highly consistent detection solution for innovative antibody drug development.
Human IgG (Human Immunogloblin G) is widely used in various branches of immunology and molecular biology. It can be used as a macroglobulin in biochemical research, or as an antigen in immunology and clinical medicine. In recent years, with the rise of immunotherapy drugs, a large number of antibody drugs based on human IgG have emerged, which has also created new demands for human IgG detection tools.
To support IgG drug development and detection, AlpVHHs leverages its stable recombinant antibody production technology and superior protein conjugation technology to provide users with high-quality, multi-application anti-human IgG nanobody, offering comprehensive solutions for researchers to address various personalized detection needs and problems related to human IgG.
Recombinant Secondary Antibody is a series of products toward the immunoglobulins from different species(mouse, rabbit, human, cynomolgus, rat, goat, alpaca,etc.)
By fusing single domain antibody(Nanobody, VHH) derived from the variable regions of heavy chain of Alpaca pacous to Fc segment (rabbit IgG), AlpVHHs offers a range of antibody products, including naked antibody, Biotin or HRP labeled antibody, fluorescent molecular labeled antibody. Those products are useful and efficient for Western Blotting(WB), Enzyme Linked Immunosorbent Assay(ELISA), Immunoprecipitation(IP), Immunofluorescence(IF), Immunocytochemistry(ICC), Flow Cytometry(FCM), Immunohistochemistry(IHC) , etc.
AlpVHHs recombinant secondary antibody products are developed based on a stable recombinant expression system and a high-precision protein design platform, and have the following significant advantages compared to traditional polyclonal secondary antibodies:
● Strict validation
All the antibodies are verified by multiple test, and specificity is guaranteed. All the antibodies are selected with high affinity (nM level), and the applications of the antibodies are clear. Using the antibodies provided by AlpVHHs, The accuracy of experiment is guaranteed.
● Stable supply
The molecular sequence of antibody is defined, and stable cell lines for recombinant expression have been constructed. Dependable and stable supply is guaranteed. Lot-to-lot difference can be eliminated by stable production and supply.
● Superior Performance
All the products are tested before delivering to customer. Consistent and reproducible results are guaranteed.
● Special Technology
Eliminating Fc binding to FcR by Fc segment specific mutation.
● Ethical issues
Limited chemical component medium for recombinant expression, no animal serum or other animal derived components are used.
The CH3 domain is a crucial component of the Human IgG Fc region, playing a key role in maintaining antibody stability and FcRn-mediated cycling. It is also a critical region for antibody engineering.
In Fc-engineered antibodies (such as KIH bispecific antibodies and YTE long-acting antibodies), the CH3 region often serves as a key modification site, but this also leads to a decrease in the recognition ability of traditional secondary antibodies.
Fig. Schematic diagram of Human IgG structure and its recognizable domains
To address these challenges, AlpVHHs has launched the Anti-Human IgG (CH3 Fragment Specific), AlpSdAbs® VHH series. Developed based on nanobodies (VHH) and recombinant expression technology, this product enables stable recognition of the following structures:
● Wild-type Human IgG
● KIH bispecific antibody structures
● Fc-engineered mutant antibodies
● Multiple IgG subtypes and modified forms
Providing more reliable detection tools to support antibody drug development.
CH3 fragment-specific antibody: Specifically recognizes the Human IgG CH3 fragment, with a well-defined recognition location and high specificity.
Specifically binds to the CH3 fragment of Human IgG without cross-reactivity with other fragments, ensuring accurate and specific detection signals that truly reflect the characteristics of the antibody drug. This is particularly suitable for characterizing Fc-engineered antibody drugs.
Nanobodies (VHH) do not contain Fc fragments, fundamentally eliminating non-specific binding caused by Fc receptors. This makes them suitable for background-critical detection techniques such as flow cytometry and immunohistochemistry, resulting in clearer and more accurate results.
Recombinant monoclonal antibody expression is strictly controlled throughout the production process, resulting in minimal batch-to-batch variation. The clone's sequence, affinity (Kd), and specificity are rigorously characterized and quality-controlled, ensuring excellent reproducibility and meeting the stringent requirements of drug development.
Offers a variety of labeling formats, including HRP, Biotin, PE, APC, iFluor488, iFluor594, and iFluor647, which can be widely used for accurate quantitative detection on platforms such as ELISA, WB, Flow Cyt, ICC/IF, and IP, meeting the needs of different experimental platforms and application scenarios.
Anti-Human IgG(CH3 Fragment specific), AlpSdAbs VHH(HRP) （Code: 023-113-005）
(1) Validation data of antibodies against different mutants
ELISA results showed that Anti-Human IgG (CH3 Fragment specific), AlpSdAbs VHH (HRP) (Code: 023-113-005) can simultaneously recognize multiple Human IgG1 mutants, including WT, LALA, LALA+YTE, and KIH.
(2) Validation data for different types of antibodies
ELISA results showed that Anti-Human IgG (CH3 Fragment specific), AlpSdAbs VHH(HRP) (Code: 023-113-005) exhibited high affinity binding to both intact Human IgG and Human IgG-CH3 fragments, demonstrating its specificity in accurately recognizing the CH3 domain.
AlpVHHs' recombinant nano-secondary antibody series provides efficient and reliable detection tools for antibody drug development, characterized by precise fragment specificity, excellent signal-to-background ratio, and stable industrial production standards. From Human IgG CH1 to Human IgG CH2, and now CH3-specific nano-secondary antibodies, Critical Point Biotech continues to innovate in antibody detection tools. The Anti-Human IgG (CH3 Fragment specific) AlpSdAbs VHH series of specific nano-secondary antibody precisely solves the detection challenges of Fc-modified antibodies, safeguarding innovative drug development and ensuring accurate and reliable testing every time!
Code | Description | Application |
023-113-010 | Flow Cyt | |
023-113-011 | Flow Cyt | |
023-113-004 | Anti-Human IgG(CH3 Fragment specific), AlpSdAbs® VHH(Biotin) | ELISA, IP |
023-113-005 | WB, ELISA | |
023-113-007 | Anti-Human IgG(CH3 Fragment specific), AlpSdAbs® VHH(iFluor488 ×4) | WB, ELISA, ICC/IF, Flow Cyt |
023-113-008 | Anti-Human IgG(CH3 Fragment specific), AlpSdAbs® VHH(iFluor594 ×4) | WB, ELISA, ICC/IF, Flow Cyt |
023-113-009 | Anti-Human IgG(CH3 Fragment specific), AlpSdAbs® VHH(iFluor647 ×4) | WB, ELISA, ICC/IF, Flow Cyt |
023-413-001 | Anti-Human IgG(CH3 Fragment specific), AlpHcAbs® Goat antibody | ICC/IF, Flow Cyt, IP, WB, ELISA |
023-413-004 | Anti-Human IgG(CH3 Fragment specific), AlpHcAbs® Goat antibody(Biotin) | IP, WB, ELISA |
023-413-005 | Anti-Human IgG(CH3 Fragment specific), AlpHcAbs® Goat antibody(HRP) | WB, ELISA |
