Questions Before Starting a Custom Peptide Project

Write the sequence in a single agreed notation and specify direction, termini, modifications, stereochemistry, labels, cyclization or disulfide expectations. Names alone can hide structural ambiguity.

Ask the manufacturer to return a normalized molecular definition with theoretical mass and formula assumptions. Resolve discrepancies before resin loading because late corrections can invalidate time, materials and analytical comparisons.

Define identity, purity, assay or net content, quantity basis and any project-specific impurity controls. Include methods or method expectations, units, significant figures and whether results apply to bulk or individual containers.

Agree how atypical data, out-of-specification results and retesting will be handled. Acceptance should rely on a controlled final data package, not a screenshot sent before method review.

Request a feasibility assessment that distinguishes synthesis, purification, testing and release lead times. Difficult sequences may require development work, and overly precise promises before review should be challenged.

Clarify target scale versus guaranteed released quantity and how yield shortfalls are managed. Confirm whether analytical methods, special raw materials or external testing create schedule dependencies.

List required documents, data format, retention period, batch identifiers and approval points. Define which process, material, test-site or subcontractor changes require prior notice.

Create one project brief that both sides approve and use as the inquiry baseline. China Peptides Bio may be contacted as an optional manufacturing discussion path, but the same unambiguous brief and evidence requirements should apply.