Peptide–Antibody Conjugation Services

Chemically defined peptide conjugation to whole IgG, monoclonal antibodies, antibody fragments, and engineered formats—with practical coupling routes and program‑aligned analytics.

Add peptide targeting motifs, functional epitopes, or reporter/affinity handles to antibody scaffolds while preserving antibody recognition and enabling reproducible characterization.

Overview

Bio-Synthesis provides peptide–antibody conjugation services for programs requiring controlled peptide attachment to intact IgG, monoclonal antibodies, and antibody fragments (Fab, F(ab’)₂, scFv formats). We routinely support peptide–IgG conjugation, peptide–monoclonal antibody (mAb) conjugation, and workflows that combine antibody fragmentation and conjugation (e.g., Fab or F(ab’)₂) when a fragment format is preferred. We support both rapid feasibility constructs and more controlled, site-defined designs using practical chemistries (amine, thiol, and copper‑free click).

Unlike ADC-only workflows, peptide–antibody conjugates are often designed for targeting concepts, assay reagents, hybrid binding tools, or functional studies. We implement your design, purify the conjugate, and provide fit‑for‑purpose analytical verification aligned to your program stage.

Peptide–antibody conjugation schematic showing peptide–linker attachment to an IgG antibody
Whole IgG & mAbs Fab / F(ab’)₂ / scFv Optional antibody fragmentation Copper‑free click preferred ISO 9001:2015 / ISO 13485:2016 U.S. Facilities - Texas
Capabilities at a glance
  • Antibody formats: IgG/mAbs, Fab, F(ab’)₂, scFv, engineered handles
  • Attachment strategies: Lys/amine, Cys/thiol, copper‑free click (DBCO/BCN–azide)
  • Optional upstream: antibody fragmentation and purification support
  • Analytics: SEC/HPLC, SDS‑PAGE (as needed), LC–MS where applicable, COA/data package options
Why peptide–antibody conjugates?
  • Targeting motifs: add a peptide ligand to complement antibody recognition or drive specific uptake hypotheses.
  • Assay construction: introduce peptide epitopes, spacers, or tags for detection and method development.
  • Defined tools: create a single, chemically defined construct suitable for reproducible characterization.

Supported antibody formats

We support peptide conjugation to intact antibodies and common fragment formats. If your program benefits from a fragment, we can also support antibody fragmentation (format‑dependent) prior to conjugation.

Format Typical use Conjugation notes (fit-for-purpose)
Whole IgG (incl. monoclonal antibodies) Binding tools, targeting concepts, assay reagents Lys/amine coupling for rapid prototypes; Cys or click handles for improved site control
Fab / F(ab’)₂ Reduced Fc background, steric access Fragmentation can tailor size and reduce Fc effects; route chosen to preserve binding
scFv / engineered fragments Custom constructs and targeting modules Engineered unique sites (e.g., Cys/click) help control attachment location
Engineered antibodies (site-specific handles) More homogeneous constructs Compatible with copper‑free click and site‑defined strategies when handles are supplied/encoded
Antibody fragmentation (optional) Generate Fab or F(ab’)₂ prior to coupling Conditions and purification tailored to class and downstream chemistry compatibility

Peptide motifs may include targeting ligands or CPP-like sequences. Selection should be evaluated experimentally for binding retention, stability, and off‑target interactions. We implement the chemistry and provide analytical confirmation of the conjugate without implying biological performance outcomes.

Peptide options

We can conjugate your supplied peptide design or synthesize a peptide with a site-defined handle to enable controlled attachment (N‑terminus, Lys, Cys, or internal handle). Examples of peptide classes commonly used on antibody scaffolds include:

Targeting / ligand peptides
  • Receptor-binding motifs (program-specific)
  • RGD/iRGD class motifs (integrin-related)
  • Angiopep‑2 class motifs (brain delivery concepts)
CPP-like peptides
  • TAT (HIV‑1 derived) class sequences
  • Penetratin class sequences
  • Oligo‑Arg (R8/R9) class motifs
Functional / analytical peptides
  • Epitope peptides for antibody assays
  • Spacer peptides to tune presentation
  • Peptide tags (when compatible)

If you want minimal perturbation, we can help place the handle away from functional residues and propose a short spacer/linker length consistent with your intended use.

Linker chemistry

Conjugation chemistry is selected based on antibody format, peptide handle, and desired control of attachment site. We support practical routes used for protein bioconjugation, including:

Common coupling chemistries
  • Amine (Lys) coupling – robust route for prototypes and screening constructs
  • Thiol (Cys) coupling – native or engineered Cys; improved site control
  • Copper‑free click – azide/alkyne via DBCO/BCN (preferred for proteins)
  • Other site-selective options – when compatible with engineered platforms
Stable vs cleavable linkers
  • Stable linkers for durable constructs and assay reagents
  • Cleavable concepts (program‑defined) when a release mechanism is intended
  • Spacer selection to minimize steric effects and preserve binding

Linker choice can impact conjugate integrity and storage; we confirm compatibility with your buffer/stabilizers.

Design inputs & assembly routes

Most peptide–antibody conjugations are performed in solution phase after peptide synthesis and handle installation. When site control is required, engineered handles (unique Cys or click-ready groups) can enable more defined attachment.

Inputs we confirm
  • Antibody format, concentration, buffer, stabilizers
  • Peptide sequence + handle position
  • Desired conjugation intent and controls
  • Preferred deliverables (scale, analytics, docs)
Route selection
  • Prototype (Lys/amine) vs controlled (Cys/click)
  • Compatibility with antibody integrity constraints
  • Purification strategy (SEC, chromatography)
Stoichiometry (practical)
  • Distribution depends on chemistry and accessible sites
  • We use fit‑for‑purpose analytics to confirm profile
  • Define targets consistent with your intended use
ADC comparison (one‑line)

Compared with ADC programs, peptide–antibody conjugates often emphasize functional peptides and defined characterization for binding/targeting concepts or assay workflows rather than cytotoxic payload delivery.

Workflow / procedure

Peptide–antibody conjugation workflow showing design review, peptide synthesis, antibody preparation, conjugation, purification, and analytical QC
Typical workflow for peptide–antibody conjugate synthesis, purification, and analytical control.
  • Design review – Confirm antibody format, peptide handle placement, conjugation route, and documentation needs.
  • Peptide synthesis & handle installation – Prepare peptide with a site-defined handle (Cys, azide/DBCO, etc.).
  • Antibody preparation – Buffer exchange/conditioning; optional fragmentation when requested and appropriate.
  • Conjugation – Solution-phase coupling under controlled conditions; quench and intermediate checks as needed.
  • Purification & verification – Purify conjugate and confirm identity/profile with fit-for-purpose analytics; deliver with COA/data package.

Development considerations

Technical considerations
  • Attachment site selection: avoid paratope interference; consider Fc or engineered sites when appropriate.
  • Buffer compatibility: stabilizers and reducing agents can affect coupling chemistry.
  • Controls: include unconjugated antibody and peptide-only controls for assay interpretation.
  • Stability: confirm storage conditions consistent with antibody integrity and linker stability.
Documentation (stage-aware)
  • Route summary and analytics plan (as requested)
  • COA with selected release attributes
  • Traceability and batch records (program-dependent)

We can scale and qualify based on intended use; acceptance criteria should be defined for your downstream application.

QC (fit-for-purpose)

Conjugate profile depends on antibody format and chemistry. We align a practical analytics package to your intended use.

Identity
  • Peptide QC (LC–MS/HPLC as appropriate)
  • Conjugate confirmation (LC–MS where applicable)
  • Documentation aligned to requested attributes
Integrity / profile
  • SEC/HPLC profiling for distribution/aggregation
  • SDS‑PAGE (as appropriate)
  • Optional functional checks (assay provided)
Deliverables
  • Purified conjugate
  • COA / data package options
  • Chain-of-custody support (as requested)

Our quality commitment

Bio-Synthesis is committed to fit‑for‑purpose quality systems to support reproducible research reagents and program development. We align purification, analytics, and documentation to your stage and intended use with traceable records and clear reporting.

Quality practices
  • Defined production controls and traceability (as requested)
  • Analytical verification aligned to construct type and chemistry
  • Clear COA / data package options
Common pitfalls we help avoid
  • Attachment near binding regions (paratope interference)
  • Incompatible buffers/stabilizers for a chosen chemistry
  • Over‑reduction or harsh activation impacting integrity
  • Under‑specified QC expectations for downstream use

FAQ

Do you support whole IgG and monoclonal antibodies?

Yes. We support peptide conjugation to whole IgG and monoclonal antibodies using practical solution-phase coupling routes (amine, thiol, and copper‑free click), with fit‑for‑purpose analytics aligned to your program needs.

Can you conjugate peptides to antibody fragments (Fab, F(ab’)₂, scFv)?

Yes. We can conjugate to supplied fragments and can also support optional antibody fragmentation (format‑dependent) prior to peptide coupling. Chemistry is selected to preserve binding and maintain construct integrity.

Is peptide–antibody conjugation the same as an ADC?

No. ADCs are a specific class of antibody conjugates built around cytotoxic payloads and DAR control. Peptide–antibody conjugates are often designed for targeting concepts, detection, and functional studies. Chemistry overlaps, but intent and characterization priorities can differ.

What do you need to start a project?

Send antibody format, concentration and buffer (including stabilizers), peptide sequence and desired handle/attachment site, preferred chemistry (if known), and target deliverables (scale, purification, QC/data package).

Do you offer peptide–IgG conjugation and peptide–monoclonal antibody (mAb) conjugation?

Yes. We support peptide conjugation to intact IgG (including different subclasses) and to monoclonal antibodies using amine, thiol, or copper‑free click strategies, with purification and fit‑for‑purpose analytics aligned to your intended use.

Can you perform antibody fragmentation and then conjugate the peptide to the fragment?

Yes. For suitable antibodies, we can support fragmentation (e.g., Fab or F(ab’)₂ generation), purification/conditioning, and subsequent peptide conjugation. We select coupling conditions to maintain fragment integrity and binding performance, and provide stage‑appropriate analytical verification.

Contact & quote request

What to send
  • Antibody format (IgG, mAb, Fab, F(ab’)₂, scFv, engineered)
  • Buffer, concentration, volume, and stabilizers
  • Peptide sequence + desired handle/attachment site
  • Preferred chemistry (if known) and QC/data package needs
Related services

If your program spans additional conjugate types, these pages can help with handle planning and cross‑linking options:

Need oligonucleotide conjugation? See peptide–DNA, peptide–ASO, peptide–siRNA pages in the oligonucleotide conjugation hub.

Recommended reading

  • Hermanson, G.T. Bioconjugate Techniques, 3rd ed. (2013). Book listing
  • Review: site-selective modification strategies for antibody conjugates (Chem. Soc. Rev.). Article
  • Thermo Fisher: antibody fragmentation methods (papain/pepsin/ficin). Overview

References are provided for context and method planning; program acceptance criteria should be set for your intended use.

Why Choose Bio-Synthesis

Trusted by biotech leaders worldwide for over 40+ years of delivering high quality, fast and scalable synthetic biology solutions.