Send a sequence or the specification that defines it. Pepti synthesizes, purifies, lyophilizes and fills the lot in Guangzhou, then issues a batch Certificate of Analysis with the HPLC purity result and the mass-spectrometry identity result. Minimum 100 kits, typically 15 days after specification and payment confirmation.
Custom synthesis here means a peptide that is made to your sequence rather than taken from a catalogue. You define the sequence, the purity target, the fill per vial and the number of vials; Pepti builds the peptide by solid-phase synthesis, purifies it by preparative HPLC, confirms identity by mass spectrometry, freeze-dries it at the specified fill and ships it in ten-vial kits with the lot's certificate.
It is a research-use service. The lot is characterized by chromatographic purity and molecular-weight identity, which is what a research buyer needs to confirm that the vial contains the sequence ordered at the purity agreed. It is not a drug-substance service: there is no GMP certificate, no drug master file and no claim of suitability for any use in people or animals. Buyers who need that should look for a licensed drug-substance manufacturer rather than a research-peptide factory.
Two practical consequences follow. First, the minimum order is a production-scale quantity, 100 kits, because the synthesis and purification set-up is the same whether the batch is small or large. Second, the deliverable is a documented lot, not a vial with a label: the certificate, the HPLC result and the MS result are part of the product.
Within scope
Confirmed case by case at RFQ
If an item is not confirmed in writing in the quote, assume it is not included.
The minimum order for a custom sequence is 100 kits. One kit holds 10 vials, so a minimum run is 1,000 vials of one sequence at one fill per vial. The lead time is typically 15 days after the specification is confirmed and payment is received. Both numbers are the factory's confirmed starting points, and the quote restates them for your specific order.
The clock starts at confirmation, not at first contact. A specification that goes back and forth for a week does not shorten synthesis; it delays the start. The fastest route to a lot is a complete specification on the first message, which is what the specification guide is for.
What can lengthen the 15 days: a long sequence, residues that couple slowly, aggregation during synthesis, a purity target that needs extra preparative passes, and modifications that add steps after cleavage. The quote states the expected lead time for the sequence as specified, and if the factory cannot see the sequence it cannot state one.
100 kits = 1,000 vials, one sequence, one fill per vial.
Typically 15 days after specification and payment confirmation. Stated per order in the quote.
10 lyophilized vials, sealed, labelled with the lot code.
Reported by HPLC against the target in your specification. The public COA library for catalogue lots shows 98.4%–99.8%; a custom lot is reported on its own certificate.
Observed molecular weight by MS, compared with the theoretical value calculated from the sequence.
Insulated carton with ice packs; tracking reference sent with the document set.
Not published. Quoted per specification.
A custom order moves through seven steps. Each has an input the previous step must deliver, an output the next step waits for, and an owner. The buyer owns the first step and signs off at two points later; everything else is on the factory side. The process page covers delays and sign-offs in more detail.
The buyer sends the sequence written one-letter or three-letter, N-terminus to C-terminus, with any modifications stated explicitly; the purity target; the fill per vial; the number of kits; the labelling; and the documents required with the shipment.
Sequence, purity target, fill, kit count, label, document list
Specification sheet returned for confirmation, written quote with lead time
Production reviews the sequence for length, difficult couplings, aggregation risk and any requested modification, then confirms or adjusts the lead time and purity target. Anything outside routine scope is answered here, in writing, before money changes hands.
Draft specification
Confirmed specification, confirmed lead time
The buyer confirms the specification sheet and pays. The lead time counts from here.
Signed-off specification, payment received
Production slot scheduled, lot code assigned
The sequence is assembled on resin, cleaved, and purified by preparative HPLC. Fractions are pooled to meet the purity target and checked by analytical HPLC; identity is confirmed by mass spectrometry.
Confirmed sequence and purity target
Purified pool with analytical HPLC and MS data
The purified solution is dispensed at the specified fill into vials, freeze-dried, capped and sealed.
Purified pool, fill per vial, vial count
Sealed lyophilized vials
Vials receive the approved label with the lot code and are packed ten to a kit. QC issues the batch COA with the HPLC purity result and the MS identity result, and assembles the other documents agreed in the specification.
Approved label proof, sealed vials, analytical data
Labelled kits, batch COA, document set
Kits are packed in an insulated carton with ice packs. The courier collects, and the tracking reference goes to the buyer with the document set. The receiving checklist covers what to check on arrival.
Labelled kits, document set, destination details
Tracking reference, delivered lot
The product of a custom order is a documented lot. The list below is what every custom lot includes; anything else, such as a certificate for a specific additional test, is written into the specification and priced there. The quality page explains what each result proves and what it does not.
One point worth stating early: a certificate reports measured results for the lot. It does not prove fill quantity by itself, microbial status, or suitability for any use. Buyers who want an independent check are welcome to send vials to a laboratory of their choosing; a documented lot makes that comparison possible.
Batch Certificate of Analysis Lot code, sequence or compound name, fill, manufacturing date, retest date, HPLC purity result, MS identity result and the conclusion against the specification.
Analytical HPLC purity The chromatographic purity of the pooled, lyophilized lot, stated as a percentage.
Mass-spectrometry identity The observed molecular weight compared with the theoretical molecular weight calculated from the sequence.
Lot-coded vial label Neutral or private-label artwork carrying the lot code that appears on the COA.
Packing list Kit count, vials per kit, carton count and the courier reference.
Confirmed specification sheet The sheet both sides signed off, kept with the lot file so a repeat order starts from the same document.
A quotable request has six fields. Missing any one of them produces a question instead of a quote, and the lead time does not start until the sheet is complete. The specification guide gives a template with examples of each field written well and written badly.
Add the destination country so the shipping method and cold-chain packing can be stated in the same quote.
Send it now
Open WhatsApp with a pre-filled Pepti-RFQ message, paste the six fields, and the sales desk answers from the factory floor. Email works the same way.
Account name on WhatsApp: Pepti Supply. Contact: Mike.
Scope statement
Pepti does not present itself as a cGMP drug-substance (API) manufacturer or CDMO and does not publish a GMP certificate or DMF. Peptides on this site are supplied for research use by qualified B2B buyers. For research use only. Not for human or veterinary use.
Custom peptides from this desk are supplied to qualified B2B buyers for research use. Pepti does not provide dosing, protocol or treatment advice and does not sell to consumers. The buyer is responsible for confirming that the sequence and its labelling are permitted in the destination market and for any permits the destination requires. Pepti does not synthesize sequences it is not permitted to make, and reserves the right to decline a sequence at the feasibility step.
Routine linear sequences built from the 20 standard amino acids are within scope. Length beyond routine ranges, modifications, non-standard residues, cyclization and conjugation are reviewed at the feasibility step and confirmed in writing or declined. Pepti also declines sequences it is not permitted to make.
Milligram-scale custom synthesis is a laboratory service priced per milligram. Peptimake is a production desk: the deliverable is a lyophilized lot in sealed vials with a batch certificate, and the synthesis, purification and fill set-up cost the same whether the run is small or large. 100 kits (1,000 vials) is where that set-up is spread thinly enough to quote sensibly. The MOQ guide shows the arithmetic.
Synthesis, cleavage, purification, analytical checks, lyophilization, fill, labelling, certificate and packing, counted from the day the specification is confirmed and payment is received. It excludes the time spent completing the specification and the courier transit. It is a typical figure stated per order in the quote, not a fixed commitment.
The purity you specify, reported by analytical HPLC on the lot certificate. Higher targets add purification passes and are confirmed at feasibility. For reference, published HPLC purity across the public COA library of catalogue lots is 98.4%–99.8%.
Bulk lyophilized powder is a standard format for catalogue compounds, from 5 g, shipped cold chain. For a custom sequence, bulk format is confirmed case by case at RFQ.
No. Custom synthesis here is research use and non-GMP. Pepti does not present itself as a cGMP drug-substance (API) manufacturer or CDMO and does not publish a GMP certificate or DMF.
Open WhatsApp with a pre-filled Pepti-RFQ message, or email the same details. A quote needs the compound or sequence, fill per vial, vial count, labelling and the document set you require.