Custom Peptide Library Synthesis

High-throughput, sequence-defined peptide libraries built to your design — ideal for epitope mapping, lead discovery, SAR, and immunology screening. Choose library format, peptide length/offset, purity, and delivery in plate-ready layouts with robust QC.

Overview

Our custom peptide library synthesis service is part of our peptide synthesis services and produces collections of peptides designed for systematic screening. We support libraries for linear epitope mapping (overlapping peptides), residue importance studies (alanine or positional scanning), focused motif exploration, and custom experimental designs.

Ideal for epitope mapping, screening, and SAR. Send your target sequence(s) and assay context — we can recommend peptide length, offset, controls, and deliverable format.

Custom peptide library delivered in labeled 96-well plates with plate map
ISO 9001:2015/ISO13485:2016 45+ Years of Expertise U.S. Facilities - Texas High‑Throughput Production Confidential & IP‑Protected
Library design
  • Peptide length, overlap/offset
  • Controls, replicates, randomization
  • Focused vs. unbiased diversity
Deliverables
  • Individual peptides or custom pools
  • 96-well / 384-well formats
  • Tube arrays or plates with map
Quality & add-ons

Library specifications

Typical ranges shown below. Exact specs depend on library size, sequence complexity, and required deliverables.

Parameter Standard options Notes
Peptide length 6–30+ amino acids Overlapping libraries commonly 8–25 aa depending on assay.
Library size 24 peptides → 10,000+ peptides Delivered as individual peptides or pooled sets.
Purity Crude, ≥70%, ≥90%, ≥95% Choose per application and budget; mixed-purity strategies are possible.
Quantity / scale µg–mg per peptide (project-dependent) Common screening scales supported; higher amounts available for selected hits.
Formulation Lyophilized (default) Other formulations by request.
QC MS identity; optional HPLC COA and sequence list/plate map included.
Delivery format 96/384 well plates or tube arrays Custom layouts and labeling available.
Counterion TFA (standard); alternatives by request Counterion preferences may be important for certain bioassays.
Get a Library Quote FAQ

Library formats we build

Overlapping peptide libraries

Systematically cover an entire protein or region using partially overlapping peptides for high-resolution mapping.

  • Define length (e.g., 8–25 aa)
  • Define offset/overlap (e.g., 1–10 aa)
  • Perfect for B/T-cell epitope mapping
Alanine scanning libraries

Identify critical residues by substituting alanine (or another residue) at each position across a lead sequence.

  • Single-point substitutions
  • Optional N/C terminal variants
  • Ideal for SAR and functional mapping
Positional scanning libraries

Probe sequence space by fixing positions and varying others with defined amino acid sets.

  • Custom AA sets (natural, selected, non-natural)
  • Focused motif discovery
  • Screening-friendly design
Focused / rational libraries

Explore variations around a known motif or binding region with rational constraints.

  • Conservative substitutions
  • Charge/hydrophobicity tuning
  • Truncation and optimization sets
Combinatorial libraries

Generate broader diversity for screening programs with controlled complexity and deliverable format.

  • Defined size & redundancy
  • Individual peptides or pooled sets
  • Customized plate maps
Custom pools / peptide sets

Receive pools grouped by region, function, or assay design, with optional pre-/post-pooling verification.

  • Pool composition per your plan
  • Optional marker-peptide verification
  • Aliquoting available
Peptide library designing tool

Build overlapping libraries, scanning libraries, and other common formats using our online design tool, then send the output to us for synthesis.

Open the Design Tool Request a Quote

How it works

A simple, screening-ready workflow

Share a target sequence (or a list of peptide sequences) and choose the library format. We synthesize, verify, and deliver your library in plate/tube layouts with the documentation you need to run assays fast.

  • Design: choose length/overlap, scanning plan, controls, and optional modifications
  • Synthesize: high-throughput SPPS with consistency-focused process controls
  • QC: MS identity (optional HPLC) plus COA/data package
  • Format: 96/384 layouts, tube arrays, pools, and plate maps
  • Deliver: ship dry with handling guidance
Design
Tool / Upload
Synthesize
HT SPPS
QC
MS / HPLC
Format
Plates / Tubes
Deliver
Map + COA

QC, modifications & add-on services

Analytical options
  • Mass spectrometry (identity confirmation)
  • Optional HPLC purity analysis
  • Custom documentation / COA packages
Modifications & bioconjugation
  • N- / C-terminal modifications
  • Cyclization (incl. disulfide where applicable)
  • Phosphorylation, acetylation, methylation (project-dependent)
  • Labels and linkers; peptide bioconjugation available

Targeted quantitative LC‑MS/MS peptide libraries

For workflows that require consistent, assay-ready reference peptides, we can produce libraries as individual peptides (plate/tube arrays) with optional stable‑isotope labeling, PTM panels, and documentation that supports streamlined method setup and data review.

Typical deliverables
  • Array delivery: 96‑well / 384‑well layouts or individual tubes
  • Plate map: sequence list + positions (CSV/Excel available)
  • Identity confirmation: MS options from spot-check to 100%
  • Handling: lyophilized or solution format (project-dependent)
Assay-friendly design options
  • Enzyme-aligned peptides: configurable C‑terminal residue preferences (e.g., Lys/Arg)
  • Length range planning: choose a length window appropriate for your method
  • Pooling strategy: custom pools or tiered pools by protein/pathway
  • PTM panels: phospho, acetyl, methyl and other site-specific variants
Stable‑isotope labeling

Common heavy labels are available on request (single peptides or full libraries).

Residue Typical label Use
Lys (K) 13C / 15N Quantitative reference peptides
Arg (R) 13C / 15N Quantitative reference peptides
Leu / Ile (L/I) 13C / 15N Targeted assays & calibration
Phe / Val / Pro 13C / 15N Targeted assays (project-dependent)

Tell us your preferred enrichment level and reporting needs.

QC tiers (example)

Select the QC depth that fits your workflow and budget.

  • Essential: standard QC + project COA
  • Standard: expanded MS coverage + plate map package
  • Comprehensive: MS on each peptide and optional data package
PTM & MS-focused options
  • Phosphorylation (Ser/Thr/Tyr)
  • Cys protection (e.g., carbamidomethylation)
  • Oxidation variants (e.g., Met(O))
  • Acetylation / methylation / dimethylation
  • Ubiquitin remnant motif panels (project-dependent)
Request a Quote Use the Library Design Tool

Common applications

Epitope mapping

Linear epitope discovery for antibodies, B-cells, and T-cells using overlapping peptide sets.

Lead discovery & screening

Identify binders and bioactive sequences with focused or combinatorial library strategies.

SAR & optimization

Alanine scanning, truncation, and rational substitutions to pinpoint key residues and improve performance.

Kinase / protease studies

Substrate libraries and modified peptides for signaling and enzymology workflows.

Antibody & vaccine research

Map immunogenic regions and test candidate sequences efficiently in plate-ready formats.

Proteomics methods

Peptide panels and libraries for method development and targeted assays (project-dependent).

FAQ

What information do you need to quote a peptide library?

Send sequences (or target protein/regions), desired library format (overlap/offset or scanning plan), quantity per peptide, purity requirements, delivery format (plate/tubes), and any modifications/QC add-ons.

Do you provide tools to design overlapping or scanning libraries?

Yes — use our online peptide library designing tool to generate common library formats and export sequences for synthesis.
https://new.biosyn.com/peptidescreeningtools.aspx

Can you deliver libraries in 96-well or 384-well layouts?

Yes. We can deliver libraries in plate-ready layouts or tube arrays and provide a map (sequence list + positions) to streamline screening.

What QC is included?

Typical QC includes MS identity confirmation with COA. Optional HPLC purity analysis and custom data packages are available.

Can you pool peptides after synthesis?

Yes — we can prepare custom pools according to your specification, with optional verification strategies depending on project needs.

Do you support stable-isotope labeled peptides for quantitative LC‑MS/MS?

Yes. We can incorporate common 13C/15N labels (e.g., Lys/Arg) on individual peptides or across an entire library. Share your sequences, preferred labeling strategy, and any reporting requirements.

Can you build targeted quantitative LC‑MS/MS libraries with enzyme-aligned peptide ends and plate-ready delivery?

Yes. We can align sequences to your method needs (for example, preferred C‑terminal residues), deliver in 96/384 layouts or tube arrays, and provide plate maps. Optional PTM panels and data packages are available.

How do I store peptide libraries?

Libraries are typically supplied lyophilized. Store sealed containers as recommended in the handling guide/COA and minimize moisture exposure after opening.

CONTACT US

Talk to a peptide library specialist

Share your target protein/regions or sequence list, preferred library format (overlap/offset or scanning plan), quantity per peptide, purity, plate/tube delivery, and any modifications or QC add-ons. We’ll recommend a practical specification and provide a quote.

Tip: For large libraries, attach a spreadsheet (one sequence per line) and include any required controls/replicates.

Need help designing the library? Use our online tool: Peptide Library Design Tool.

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