Met-Enkephalin is supplied as white lyophilized powder with molecular formula C27H35N5O7S and molecular weight 573.7. Met-enkephalin is a pentapeptide opioid neurotransmitter with the sequence tyrosine-glycine-glycine-phenylalanine-methionine, first identified in brain tissue in the 1970s. It is used extensively in delta and mu opioid receptor binding studies and in analgesia research, where its short half-life makes it suitable for acute exposure designs. Neuropharmacology laboratories apply it to pain signaling, reward behavior and stress response models. As a small well-characterized peptide it also serves as a calibration standard in mass spectrometry and immunoassay method development. YIWU SHUNXIAN TRADING CO., LTD. supplies high-purity research-grade peptides and laboratory consumables to research organisations in many countries, with an emphasis on predictable quality and clear commercial terms. Material is sourced against agreed specifications, purified and lyophilized under controlled conditions, then released on the basis of analytical results rather than visual inspection alone. We keep the ordering process simple: a written quotation states the pack size, price and shipping option, and a dispatch confirmation states the tracking number. Research groups that need recurring supply can arrange a standing specification so that successive orders remain comparable. Every lot is analysed by analytical HPLC with a C18 stationary phase and a shallow acetonitrile gradient, which resolves closely related deletion sequences that a fast gradient would hide. Identity is verified by LC-MS, and the measured molecular ion must fall within the tolerance specified for the theoretical mass. For peptides prone to oxidation, an additional methionine oxidation check is performed, and the result is included in the lot documentation. Each order is assembled against a packing list that is checked before dispatch, so that a multi-vial shipment arrives with the correct material, lot numbers and documentation. Vials are held upright in a partitioned insert, which prevents contact between neighbouring containers during transit. For laboratories with automated storage systems we can apply two-dimensional barcode labels carrying the catalogue number and lot identifier, allowing direct scanning into inventory records. Technical and commercial enquiries are both welcome. Message Aurora on WhatsApp at +852 4423 6619 or email 18963519387@163.com, stating the product name, the quantity needed and the destination country. If the material is required for a scheduled study, include the target date; we will then confirm whether the requested transit window can be met and, if not, propose the closest workable alternative. Where a study extends beyond a single working session, plan the storage format before reconstituting. Divide the contents into aliquots sized for one experiment, freeze them rapidly, and label each tube with the peptide name, concentration, buffer and date. Keep the stock vial sealed and cold between weighing sessions. This approach limits the number of thaw events, which is the most common cause of gradual potency loss in peptide research. Shipments are booked with a service level appropriate to the destination. For nearby regions, standard tracked courier is normally sufficient; for intercontinental routes we favour express services with shorter transit and better milestone visibility. Parcels are handed over with a commercial invoice that matches the declared contents, which helps avoid clearance delays. A tracking number is issued at handover and can be checked until final delivery.