Anti-Human IgG Fc, AlpSdAbs® VHH(VcMMAF ×4) is a monovalent, recombinant single-domain VHH antibody designed for studying the antibody internalization. This alpaca-derived VHH specifically targets the Fc region of human IgG and is conjugated to 4 molecules of VcMMAF (a potent microtubule inhibitor) at a site-specific position. It serves as a powerful tool for functional cytotoxicity-based internalization screening and evaluation of antibody potency prior to ADC development.
Based on immunoelectrophoresis and/or ELISA, it reacts specifically with the Fc fragment of human IgG heavy chain but not with the Fab portion. It enables direct assessment of internalization-dependent cytotoxicity in live cells, making it ideal for mechanistic studies, trafficking analysis, and high-throughput antibody screening.
Technical Specifications
Immunogen | Recombinant Fc region of human IgG |
Host | Alpaca pacous |
Isotype | VHH domain of alpaca IgG2b/2c |
Conjugate | VcMMAF (2 moles VcMMAF per mole VHH) |
Specificity | Human IgG (Fcγ fragment specific), including IgG1, IgG2, IgG3, IgG4 and their mutations (LALA or YTE) |
Cross-Reactivity | Recognizes human IgG Fcγ fragment specifically, and reacts with cynomolgus IgG. No cross-reactivity with rabbit, mouse, rat, or goat IgG |
Purity | Recombinant Expression and Affinity purified |
Concentration | 0.5 mg/ml |
Formulation | Liquid, 10mM PBS (pH 7.4) |
Storage | Store at –20 °C (Avoid freeze / thaw cycles) |
Product Advantages
• VHH nano-secondary conjugated with potent cytotoxic payload VcMMAF (Two VHH Binding one IgG, DAR=4)
• Functional cytotoxicity-based internalization screening
• Evaluate internalization-dependent cytotoxicity in tumor cell models
• Rapidly compare internalization efficiency among multiple antibody candidates
• Support high-throughput screening for internalizing antibodies
• Ideal for rapid pre-selection of lead antibodies before formal ADC development
• High sensitivity with low background
• Compatible with multiple IgG subtypes (IgG1–IgG4 and common mutations)
• Simplified workflow for high-throughput assays
Discover more Nano Secondary Antibody-Drug Conjugates in this series.
Applications:
Antibody Internalization Test: 2 μg per 10 μg test antibody (molar ratio = 2:1)
Dilution factors are presented in the form of a range because the optimal dilution is a function of many factors, such as antigen density, permeability, etc. The actual dilution used must be determined empirically.
Background
VHH are single-domain antibodies derived from the variable regions of the heavy chain of Camelidae immunoglobulin. The size of VHH is extremely small(<15KDa) compared to other forms of antibody fragments, which significantly increases the permeability of VHH. Thus, VHH is considered of great value for research, diagnostics, and therapeutics.
VcMMAF is a potent microtubule-disrupting toxin commonly used in antibody-drug conjugates (ADCs).
Ordering & Support
• Request COA or Quality Certificate for detailed batch information
• Contact Technical Support for dilution recommendations or application guidance
