Antibody Engineering Service

Alfa Cytology - ADC Development Platform

Leveraging the DuoADC^TM platform, we design dual-target antibodies with optimal affinity, specificity, and payload compatibility to unlock next-generation ADC performance. Combining an end-to-end biologics toolbox with deep expertise in complex protein engineering, Alfa Cytology delivers antibody-engineering solutions that advance your programs with speed and scientific rigor.

Overview of Antibody Engineering

Antibody engineering integrates structure-guided mutagenesis, synthetic library construction, and display-based selection to optimize variable-domain affinity, specificity, and developability. Framework resurfacing and humanization minimize immunogenic epitopes, whereas Fc-region reprogramming modulates complement recruitment, half-life, and neonatal receptor recycling. Multispecific architectures—bispecific, biparatopic, or dual-target formats—are assembled via orthogonal pairing strategies and site-specific conjugation handles, enabling precise payload or label attachment.

Fig 1. Illustration of four classes of antibody formats. (LOU H, et al., 2022)

Classification of Antibodies

Full-Length Monoclonal Antibodies

Unmodified heavy- and light-chain tetramers that retain natural Fc-mediated effector functions and long circulatory half-life, providing a foundational scaffold for further engineering.

Antibody Fragments (Fab, scFv, Diabody)

Truncated formats lacking an Fc region; their reduced size improves tissue penetration and enables multivalent assembly, but requires additional strategies to extend serum persistence.

Single-Domain Antibodies (VHH / single domain antibody)

Derived from camelid heavy-chain–only repertoires, these ~15 kDa domains combine high stability with access to recessed epitopes unreachable by larger molecules.

Bispecific and Multispecific Constructs

Engineered to recognize two or more distinct antigens or epitopes, they employ orthogonal pairing designs (e.g., knob-into-hole, CrossMab) to ensure correct heavy/light-chain assembly and balanced affinities.

Our Services

Alfa Cytology specializes in platforms for affinity maturation and Fc engineering, with a focus on optimizing bispecific antibodies. Supported by comprehensive analytical characterization, we collaborate with clients to guide each project from initial design to the development of fully optimized bispecific antibody candidates.

Antigen Epitope Assessment & Immunogen Design

Defines distinct, non-overlapping epitopes for each target and prepares conformationally faithful immunogens to seed antibody discovery campaigns.

Diverse Library Construction & Lead Isolation

Employs phage, yeast, or mRNA display libraries to retrieve high-affinity binders against both antigens, delivering a ranked panel of single-specific leads.

Affinity and Specificity Enhancement

Applies error-prone mutagenesis and focused residue scanning to refine kinetic constants and eliminate cross-reactivity with homologous proteins.

Bispecific Architecture Assembly

Uses orthogonal pairing motifs and engineered linkers to build dual-target formats that retain independent binding while supporting controlled payload loading.

Fc-Region Modulation

Introduces targeted amino-acid substitutions and glycan tuning to adjust recycling, effector engagement, and overall serum persistence.

Site-Selective Conjugation Handle Engineering

Incorporates engineered cysteines or enzymatic tags into defined positions, enabling homogeneous dual-payload attachment with predictable stoichiometry.

Workflow of Antibody Engineering

Target Pair Definition & Epitope Mapping
Bioinformatic and structural analyses identify two complementary antigens and delineate non-overlapping epitopes, establishing a blueprint for dual-specific binder discovery.

Lead Discovery & Sequence Optimization
Combinatorial display libraries yield high-affinity monospecific antibodies for each epitope; humanization and liability pruning then refine developability, stability, and expression.

Bispecific Construction & Developability Verification
Orthogonal pairing motifs fuse the optimized arms into a single construct, after which biophysical assays confirm correct chain assembly, solution robustness, and payload-compatible conjugation readiness.

Alfa Cytology unites seasoned protein-engineering know-how with proven discovery and optimization workflows to generate antibody constructs meeting strict affinity, stability, and manufacturability goals. If you have questions or would like to explore how our antibody engineering service can advance your program, please contact us anytime.

Reference

LOU H, CAO X. Antibody variable region engineering for improving cancer immunotherapy [J]. Cancer communications (London, England), 2022, 42(9): 804-27.

For research use only, not for clinical use.

DuoADC™: Precision Engagement, Amplified Efficacy

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Please note that we are not a pharmacy or clinic, so we are unable to see patients and do not offer diagnostic and treatment services for individuals.