Peptide libraries
Parent sequence in, scan library out — every variant synthesized side-by-side under identical conditions, with a single lot number for the whole set.
What researchers use libraries for
Epitope mapping
Locate the linear B-cell or T-cell epitope in a protein antigen using overlapping or truncation scans.
SAR exploration
Map structure–activity relationships across a lead peptide with alanine and positional scans.
Binding-site profiling
Identify key residues in peptide–protein or peptide–receptor interactions before larger campaigns.
Substrate screening
Build a panel of substrate candidates for proteases, kinases, or other enzymes in one run.
Scan types we synthesize
Alanine scan
Every residue swapped to alanine in turn — isolates which positions are functionally required.
Truncation scan
N- or C-terminal residues removed one at a time — finds the minimum active sequence.
Overlapping scan
Sliding-window N-mers across the parent (typical: 12-mers, 4-residue offset) — covers the full sequence space.
Positional scan
Every residue at one chosen position replaced by each of the 19 other canonical amino acids — finds the optimal residue at that site.
Order envelope
- Library size
- 24–500 peptides per order
- Scale per peptide
- 1–5 mg typical (contact us for larger)
- Purity tiers
- Crude · >85% · >95%
- Delivery format
- Lyophilized vials or 96-well plates
- QC included
- HPLC + MS, lot-shared Certificate of Analysis
- Lead time
- 4–6 weeks for libraries up to ~100 peptides; longer libraries scheduled around capacity
Modifications we support
Special amino acids
- D-amino acids
- Phospho-Ser / Thr / Tyr
- Methylated lysines
- Citrulline
- Hydroxyproline
- Ornithine
- Norleucine
- Homoserine
- Isotope labels (¹³C, ¹⁵N)
Termini & labels
- N-acetyl
- N-formyl
- Free amine (N-terminus)
- C-amide
- C-acid
- FITC
- Biotin
- Dansyl
- Rhodamine / TAMRA
- Fatty-acid lipidation
How a library order runs
Feasibility review
Send the parent sequence + scan type. We confirm scope, flag risky residues, and quote within 24–48 hours.
Parallel synthesis
All variants run side-by-side on identical scale under the same chemistry. 4–6 weeks for libraries up to ~100 peptides.
Per-peptide QC
HPLC and MS for every peptide. Lot-shared Certificate of Analysis covers the full library under one lot number.
Single-lot delivery
Lyophilized vials or 96-well plates, EU-shipped with the full QC pack. Cold-chain available on request.
Frequently asked
What's the minimum library size?
We start at 24 peptides per order. Below that, the single custom peptide offering on the Model 2 parent page is usually a better fit.
Should I order crude or purified peptides?
Crude is the right choice for high-throughput screening where you're filtering for signal, not measuring potency. Purified (>85% or >95%) is needed when downstream readouts depend on clean material — affinity measurements, structural studies, or animal work.
C-terminal acid or amide for epitope screening?
C-amide is the conventional default for overlapping epitope scans — it mimics the internal peptide-bond environment of the parent protein. Use C-acid only when the natural C-terminus is included in the scan window.
How does lead time scale with library size?
Libraries up to ~100 peptides run in our standard 4–6 week window. Larger libraries (200–500) are scheduled around capacity and typically add 1–3 weeks. We confirm an exact window with the feasibility quote.
Start your library design
Send us your parent sequence and scan type — we'll come back with feasibility and a quote within 24 hours.