Custom Peptide Synthesis for Scientific Research
Reliable custom peptide synthesis for break-through research and drug discovery. Our most popular service.
QIANMIAO PEPTIDES offers custom peptide synthesis for research and manufacturing, produced in-house at our Qingdao, China GMP facility. Using Fmoc solid-phase peptide synthesis (SPPS) on automated and manual platforms, we produce sequences from short research peptides to long, heavily modified peptides.
Every custom peptide ships with a Certificate of Analysis that includes RP-HPLC purity and ESI/MALDI mass-spectrometry identity as standard. Backed by more than 30 years of peptide chemistry, our team routinely delivers "difficult" sequences — aggregation-prone, hydrophobic, and multi-disulfide peptides — that many suppliers decline.
Synthesis Capabilities
We synthesize essentially any sequence, at any scale, with the modifications your assay requires:
- Standard peptides — any sequence from 5 to 50+ residues, delivered as a lyophilized powder.
- Modified peptides — N-terminal acetylation, C-terminal amidation, phosphorylation (pSer/pThr/pTyr), succinylation, biotinylation, PEGylation, and non-natural / D-amino acids.
- Cyclic & constrained — head-to-tail cyclization and one to three intramolecular disulfide bridges with defined connectivity.
- Difficult sequences — hydrophobic, aggregation-prone, and long (>50 aa) peptides using optimized coupling and pseudoproline strategies.
Purity Grades & Scale
Choose the purity grade that matches your application. Higher purity reduces assay background but costs more, so we help you pick the right level rather than over-specifying.
- Crude (~70%) — preliminary screening, method development and non-critical applications.
- > 95% — cell-based assays, receptor binding, and most publication-grade work.
- ≥ 99% — quantitative studies, structural work, SAR, and commercial manufacturing.
Quality Control on Every Order
Nothing leaves the facility without identity and purity confirmed. Standard QC is included at no extra charge; additional analyses are available on request.
- RP-HPLC — purity chromatogram at 214/220 nm.
- Mass spectrometry — ESI-MS or MALDI-TOF identity confirmation.
- Optional — amino acid analysis (net peptide content), counter-ion exchange (TFA → acetate/HCl), and endotoxin testing for cell-culture use.
Service Specifications
| Parameter | Specification |
|---|---|
| Synthesis method | Fmoc solid-phase (SPPS) |
| Length | 5 – 50+ amino acids |
| Scale | 1 mg – multi-gram (kg on request) |
| Purity options | Crude ~70% · >95% · ≥99% (catalog standard) |
| Standard QC | RP-HPLC + ESI/MALDI-MS |
| Typical turnaround | 2 – 4 weeks (sequence-dependent) |
| Deliverable | Lyophilized powder + Certificate of Analysis |
Frequently Asked Questions
What turnaround time should I expect?
Most standard peptides ship in 2–4 weeks. Longer sequences, complex modifications, and multi-disulfide cyclization add time; we confirm a firm lead time with every quote.
Which purity grade do I need for cell-based assays?
>95% is suitable for most screening and binding work. Our catalog standard is ≥99% (HPLC), which is what you want for quantitative, structural or manufacturing use where trace impurities matter.
Can you remove residual TFA from synthesis?
Yes. TFA counter-ions can interfere with sensitive cell assays; we offer counter-ion exchange to acetate or hydrochloride salt on request.
Request a Custom Peptide Quote
Send us your sequence, target scale, purity grade, and any modifications, and our scientists will confirm feasibility, price, and lead time — usually within one business day. Contact our team to get started.