Providing end-to-end services, from antibody design to large-scale production.

Synthetic phage display platform

Synthetic Phage Display Platform

Xichang Bio currently has a storage capacity of 10. ¹¹A fully human Fab synthetic library; the ultimate goal is to establish a hundred-billion‑member fully human Fab synthetic library, dedicated to helping pharmaceutical and diagnostic‑reagent companies develop high‑affinity, highly specific antibody candidates.

Fully human single-domain (VHH) synthetic library

The fully human single-domain antibody (VHH) synthetic library combines the low immunogenicity of fully human antibodies with the high tissue penetration of single-chain structures, making it an essential tool for developing next-generation therapeutic antibodies—particularly those targeting solid tumors—while also providing a rapid screening platform for personalized medicine.

Early detection of antibodies

Rabbit Monoclonal Antibody Technology Platform

Xichang Bio—Phage Display Technology Meets Rabbit Monoclonal Antibody Development, Unlocking New Potential for High-Affinity Antibodies

Single B-cell screening technology platform

Single B-cell antibody screening is an innovative approach that rapidly generates specific antibodies by screening, expanding, and cloning individual B cells. This technology enables direct acquisition of antibody information from the immunized organism, bypassing the laborious steps of cell culture and hybridoma generation inherent in conventional screening methods, thereby significantly enhancing both the efficiency and accuracy of antibody discovery.

Alpaca Nanobody Discovery Platform

Camelid nanobodies (VHH antibodies or single-domain antibodies) are single-domain antibodies isolated from heavy-chain antibodies (HCAbs) naturally present in camelids such as llamas and camels. With a molecular weight of only about 15 kDa, they represent the smallest known functional antigen-binding units. Their unique structure and biological properties endow them with significant potential across biomedicine, diagnostics, and industrial applications.

Hybridoma Screening Platform

Hybridoma technology is an important method for producing monoclonal antibodies. Based on cell fusion, it involves fusing B lymphocytes from immunized animals with myeloma cells, followed by selection using HAT medium and specific screening, and subcloning to obtain monoclonal antibody‑producing cell lines that secrete antibodies capable of specifically recognizing the target antigen. These cell lines are then cultured in vivo or in vitro and subjected to affinity purification to yield the desired monoclonal antibodies.

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Protein expression platform

Protein Expression Platform

Stable Cell Line Construction

The CHO‑K1 Q host and its accompanying vector are of well‑defined origin and fully licensed, derived from wild‑type CHO‑K1 cells maintained at the European Collection of Cell Cultures (ECACC). The expression vector is pKS001, which employs glutamine synthetase (GS) as a selection marker under methionine sulfoximine (MSX) selection pressure. Electroporation is used, achieving transfection efficiencies of 90% or higher. We possess extensive expertise in signal peptide optimization, selection marker design, and codon optimization.

Stable expression and preparation of Pool protein

Expression levels range from 1 to 4.0 g/L; bulk pool production yields protein at the gram scale (4–5 weeks), while minipool production delivers protein at the 10-g scale (8–9 weeks).

Large-scale power-to-X platform

It is primarily used for the research and development and preclinical studies of large-molecule biologics such as antibodies and recombinant proteins, as well as for the production and preparation of IVD antigen and antibody raw materials.

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Other services

AI antibody discovery platform

Driven by a large language model–powered intelligent brain, it can seamlessly handle end-to-end tasks including antibody engineering, de novo generation, structure prediction, design optimization and modification, as well as wet-lab validation.

Custom Development of ADA Antibodies

Immunogenicity of a drug refers to its ability, or that of its metabolites, to elicit an immune response or immune‑related events against the drug itself or related proteins. As research and development of new drugs in China—particularly therapeutic protein therapeutics—continue to expand, studies on immunogenicity are becoming increasingly extensive.

Custom Development of CHO Cell HCPs

Xichang Bio offers custom development services for broad‑spectrum or highly specific HCP assays, tailored to various CHO cell lines (such as CHO‑K1, CHO‑S, CHO‑DG44, and others).

Preparation of ADC Payload Monoclonal Antibodies

ADCs are multi-domain molecules composed of a monoclonal antibody (mAb), a linker, and a small-molecule cytotoxin. As the number of ADCs continues to grow, the clinical immunogenicity risk associated with these agents has increasingly drawn significant attention from the industry. The design and development of neutralizing antibody assays for ADCs differ from those used for conventional antibody therapeutics and present substantial challenges.

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Antibody engineering transformation

Antibody engineering and modification

pH-Dependent Engineering of Antibodies

Phage‑display antibody pH‑dependent engineering service By employing a targeted histidine‑enrichment strategy, we precisely engineer the pH‑responsive properties of antibodies, enabling selective binding to the tumor microenvironment and prolonged circulation.

Antibody humanization

In antibody drug development, minimizing immunogenicity while preserving target specificity remains a central challenge for clinical translation. Leveraging its CDR‑grafting–based humanization technology, Xichang Bio provides scientifically sound solutions to clients worldwide, driving dual breakthroughs in both the safety and efficacy of antibody therapeutics.

Antibody affinity maturation

Xichang Bio is dedicated to innovation in antibody engineering, leveraging an international phage‑display technology platform to provide global clients with antibody affinity maturation services. By constructing highly diverse mutant libraries and employing intelligent screening strategies, we can rapidly optimize antibody affinity and specificity, accelerating breakthroughs in the development of therapeutic antibodies, diagnostic reagents, and biopharmaceuticals.

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Rapid drug analysis

Rapid Drug-likeness Analysis

Xichang Bio boasts extensive expertise in drug‑likeness assessment, protein engineering, candidate molecule design and expression, and in vitro efficacy evaluation for a wide range of novel molecular entities, including monoclonal antibodies, bispecific antibodies, and ADCs. This capability enables seamless integration between early‑stage drug discovery and CMC development, facilitating the advancement of superior candidates into the next phase of development.

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Customized Library Construction

Custom Library Construction

Customized Molecular Library Development Services Leveraging a phage‑display platform, we offer end‑to‑end molecular engineering solutions that address the needs of protein scaffolds, peptides, and the directed evolution of specialized protein molecules.

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