1. Public
Company role, address, public batch COAs, quality policy and compliance boundary. On this website, for anyone.
SeqLine Bio · Supplier verification
Supplier verification · buyer due diligence
Supplier verification & buyer due diligence
How to check SeqLine Bio before you pay.
SeqLine Bio is a research peptide manufacturer in Guangzhou, selling B2B for research use only. This page shows what is public, what we send after an RFQ, and how to confirm who you contract with, who you pay, who makes the lot and who tests it. For the general method that applies to any supplier, see how to verify a peptide supplier.
Procurement verification
What buyers can verify at each stage.
| Stage | What buyers can verify |
|---|---|
| Public information | Company identity, official website and contact channels, public COA library, quality policy, and research-use / B2B boundaries. |
| After a complete RFQ | The contracting entity, manufacturing site, QC arrangements, and proposed shipment lot, confirmed for the requested product and destination. |
| Before payment | The final quotation, pro forma invoice (PI), payee details, COA for the lot to be supplied, written quality-claim terms, and the named delivery place, Incoterm, importer of record and included duties/taxes. |
Before paying, check that the quotation, PI and payee details are consistent, and that the COA lot number matches the lot confirmed for your order. Ask us to resolve any discrepancy in writing.
How disclosure works
Three layers, each tied to a step of the order.
2. After a complete RFQ
The contracting entity, payee, production site and releasing QC for your order, plus the documents for the proposed lot.
3. Before payment
Contract or order confirmation, proforma invoice, beneficiary account, the COA for the lot to be shipped, and delivery terms.
Layer 1
What is public on this website.
The details of a specific order, such as the contracting entity and bank account, are confirmed in the quotation and contract, not here.
| Brand & website | SeqLine Bio · seqline.bio |
|---|---|
| Business role | Research peptide manufacturer and private-label OEM |
| Products | Research-use raw powder, lyophilized vials, private-label packaging |
| Business boundary | B2B only, research use only, no advice on human use (see compliance) |
| Contact | [email protected] and the RFQ form; official channels are listed on the company identity page |
| Address | Science City International Business Incubator Industrial Park, Huangpu District, Guangzhou, China |
| Batch documents | Public COAs with lot number, HPLC purity, MS identity and test date |
| Quality policy | Independent testing welcome; confirmed quality issues replaced or refunded (see quality) |
| Order path | Samples, bulk and private label (see sample lots, OEM) |
Layers 2 and 3
Documents you receive after an RFQ, before payment.
Once we have your company details, destination and intended research use, we send the documents for the proposed order.
With the quotation and before payment
- Legal name, country of registration and address of the contracting entity
- Proforma invoice showing the seller name and beneficiary account
- Production site and releasing QC for the lot
- COA for the lot to be shipped
- Order specification, packaging and delivery terms, including the named place, importer of record and DDP cost scope where confirmed
- Quality-claim, replacement and refund terms
Depending on product, destination and order
- Company registration documents
- Testing laboratory and tests performed
- Raw chromatograms and spectra
- Quality agreement
- Label and packaging artwork proofs
- Export and shipping documents for the destination
- Supplier declarations
- Arrangements for independent testing
Parts of a document may be redacted where they contain a partner’s confidential information. We do not issue drug-regulatory approvals or guarantee that a product may be imported into a given country; product eligibility and lawful import arrangements are confirmed before payment. The agreed delivery term assigns clearance and cost responsibilities; DDP does not replace product-specific import requirements.
Four checks
Who you contract with, who you pay, who makes it, who tests it.
1. The contract
The quotation or proforma invoice should show the seller’s full name and registered address, the product and specification, quantity, price and currency, delivery terms, the beneficiary account name, and which COA belongs to which line.
2. The payee
The beneficiary on the payment instruction should be the contracting entity, unless a different payee is authorized in writing before payment. If it differs, ask how the entities are related and how the invoice maps to the payee.
Do not pay a personal account, an unrelated individual, or an account introduced only in a chat message.
3. The manufacturing side
SeqLine Bio makes the products listed on this site. The quotation or contract names the production site and the releasing QC for your lot, and who handles quality claims.
4. The testing side
For each lot, confirm the tests performed, the test date and method, whether testing was in-house QC or an outside lab, that the COA lot number matches the lot to be shipped, and that you may re-test it.
HPLC purity and MS identity do not show sterility, endotoxin, fill weight, biological activity or suitability for human use. See COA, HPLC and MS explained.
Roles in an order
Who does what, and which document shows it.
One entity may hold several roles. The roles for your order are named in the quotation or contract.
| Role | Main responsibility | What the buyer should check |
|---|---|---|
| SeqLine Bio | Quotation, production on its own line, QC release, buyer communication | Quotation, contract, quality policy |
| Contracting entity | Signs, invoices, receives payment, carries commercial liability | Registration details, contract, proforma invoice |
| Production site | Synthesis, purification, lyophilization and packaging | Site named in the quotation or contract, batch record |
| Releasing QC | HPLC, MS and lot release | COA, test method, in-house or outside laboratory |
| Logistics / export | Shipping, customs, document preparation | Packing list, commercial invoice, shipping documents |
| Buyer’s independent laboratory | Re-tests the material received | Independent test report (see independent testing) |
Buyer checklist
Tick these before you pay.
Copy the list into your supplier file. Every line should be answered in writing.
- Contracting entity name confirmed
- Quoting entity matches the contracting entity
- Invoicing entity matches the payee, or a written authorization exists
- Beneficiary account is not a personal account
- Product, specification and quantity match the COA
- COA lot number matches the lot to be shipped
- Tests performed and testing laboratory confirmed
- Limits of HPLC / MS results understood
- Research use and destination-country requirements confirmed
- Packaging, labels and shipping documents confirmed
- Delivery term, named place, importer of record and included freight, duties and import taxes confirmed
- Quality-claim, replacement or refund terms confirmed
- Decision taken on independent third-party testing
Verification pack
Ask for the documents with your RFQ.
Include your company name, destination country, product, specification, estimated quantity and the documents you need. We reply within 4 business hours.