Recombinant protein production
Fully human antibody discovery
Antibody production
Antibody evaluation
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Antibody engineering
Affinity mautration
Antibody application
Assay development
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Recombinant antigen protein production
Recombinant protein is the most often used antigen format for antibody isolation using library panning, although sometimes combined with cell based library panning to ensure the binding of isolated antibodies to native antigens. We have developed three major systems for recombinant protein production, i.e., mammalian cell, yeast and E.coli expression systems. Mammalian cell expression system is the most often used one because most of the antigens are of human origin. In most cases, antigens of interest are extracellular domains of cell surface proteins and production of only the extracellular domain is challenging. We have developed several novel vectors for highly efficient expression of difficult expression proteins, which enables to prepare almost any recombinant antigens of interest for library panning.
Antibody discovery from yeast or phage display libraries
The premade antibody libraries we have are: 1x1011 yeast display dimmer-scFv library; 1.2x1011 yeast display monomer-scFv library; 5x105 yeast display single domain antibody library; and 2x1010 phage display Fab library.
We have developed a comprehensive library screening strategy using recombinant proteins, tag-fused proteins or cell based screening for highly efficient isolation of high affinity antibodies from both yeast and phage libraries. Provide us the recombinant protein of your antigens, or just give us the names, we will design and prepare the recombinant proteins for you, and isolate their high affinity antibodies from our libraries.
We have developed a comprehensive library screening strategy using recombinant proteins, tag-fused proteins or cell based screening for highly efficient isolation of high affinity antibodies from both yeast and phage libraries. Provide us the recombinant protein of your antigens, or just give us the names, we will design and prepare the recombinant proteins for you, and isolate their high affinity antibodies from our libraries.
Antibody production
We have developed efficient E.coli expression system for single domain antibody, scFv and Fab in intracellular or secretory way; yeast expression system for secretory production of single domain antibody and scFv; and serum free mammalian cell expression system (suspension CHO and HEK293) for all types of fragment antibody or full antibody.
Antibody evaluation
We routinely evaluate the isolated antibodies for antigen binding affinity by ELISA using recombinant antigen. Sometimes, living cell ELISA is needed to evaluate the antibody affinity to native conformation antigens on cell surface. We also provide living cell ELISA service for affinity measurement. Internalization and stability assay services are also available.
Antibody engineering
Isolated fragment antibodies usually need to be engineered to other different formats, such as full antibody or a fusion to Fc. We have developed comprehensive techniques to design these conversions among different antibody formats that the function of antigen binding is well reserved or improved. For conversion of fragment antibody to full antibody, an appropriate signal peptide and constant region need to be designed for each unique fragment antibody, and the junctions between the signal peptide and variable region, or between variable region and the constant region, need to be designed as what happens in nature to reduce possible immunogenicity. Our unique design strategy could engineer a fragment antibody to a full antibody as the same as a naturally produced one by human B cells with its native signal peptide and constant region, and without any additional amino acids.
Antibody affinity maturation
Yeast display has the advantage that antigen binding yeast population could be easily sorted using Fluorescence Assisted Cell Sorting (FACS). This enables yeast display more efficient than phage for affinity maturation because in additional to the antigen concentration management and stringent washing used in phage display, FACS is more efficient in direct sorting of higher affinity yeast populations from other medium to high affinity ones. For affinity mutation, CDR mutation will be designed based on the antibody template and a yeast display library will be constructed and panned using the antigen.
Antibody-drug conjugate
We provide services for full antibody conjugation with drug MMAE, MMAF and DM1 with cleavable or non-cleavable linker through thiol-mailemide or amine-ester reaction as well as in vitro function study of ADC.
Bi-specific antibody
We provide design, production and function analysis of bi-specific antibodies using anti-CD3 scFv and the other scFv of interest.
Antibody labeling
We provide antibody labeling services, such as fluorophore, biotin, dyes for various applications, including the near infrared dye labeling for in vivo antibody distribution study.
Assay Development
Our capabilities include assay feasibility, development, optimization, and sample analysis. Whether it is pharmacokinetic, immunogenicity or biomarker analysis, we provide rapid turnaround and consistent results for your projects. Our team has extensive experience in ELISA and enzymatic assays and the Meso Scale Discovery™ electrochemiluminesence platform. Assays are developed using best practices that will allow them to be adapted for GLP use in the future. To ensure data integrity, we perform double documentation QC for all assays. Through our network of partners, we can transition your studies to be run under GLP as needed.
Assay Types:
Assay Types:
- ELISA
- PK Immunoassays
- Receptor Neutralization
- Receptor Internalization
- Toxin Neutralization
- Serological Assays
- Enzyme Assays
- Immunogenicity Testing