We report net peptide content, not just purity — so the milligrams you dose aren't padded with water and counter-ion. RP-HPLC purity and ESI-MS identity, on a lot-numbered COA.
Net peptide content, not just purity — RP-HPLC + ESI-MS, lot-numbered COA.
Net peptide content on every lot's COA.
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Reading a peptide HPLC trace — a field guide. Read →
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28-residue vasoactive / immune neuropeptide
Lyochem primary owner
This Lyochem page is the primary SEO owner for research labs, CROs, and method-development teams qualifying VIP (Vasoactive Intestinal Peptide) as a documented research-standard lot. The page should answer whether the buyer can review HPLC purity, identity confirmation, lot continuity, stability handling, and assay-fit documentation before ordering.
Overview
A 28-residue neuropeptide within the secretin/glucagon superfamily, VIP (Vasoactive Intestinal Peptide) signals through the class-B GPCRs VPAC1 and VPAC2 to drive an unusually wide spectrum of responses, among them vasodilation, bronchodilation, dampening of macrophage- and T-cell-derived pro-inflammatory cytokines, entrainment of suprachiasmatic circadian pacemaking, and regulation of gut motility and exocrine output. That very breadth makes it a workhorse for basic research while frustrating selective therapeutic development. First recovered from porcine duodenum, it was subsequently mapped throughout both central and peripheral nervous tissue. Lyochem supplies VIP as a lyophilized reference standard at ≥99.0% HPLC. Synthesis of the 28-mer is dependable, but the critical release check is the C-terminal α-amide: because receptor binding depends on it and the free-acid form is markedly less active, mass spectrometry must resolve the amidated species at +1 Da against the free acid. Alongside that ESI-MS identity step, the packet documents peak-integration HPLC, water content, and counter-ion. Native VIP clears within roughly 1-2 minutes via DPP-4 proteolysis, an asset for acute-signaling experiments and a constraint for sustained-exposure designs; half-life-extended variants such as Aviptadil can be arranged through Lyochem's custom-synthesis programme.
Applications & buyer fit
Cognitive and neuropeptide buyers are predominantly research labs running in vivo rodent studies. The dominant administration route in the published literature is intranasal — Semax, Selank, DSIP, Pinealon — because these peptides are not meaningfully blood-brain-barrier permeable when delivered systemically. For in vivo workflows, endotoxin and microbial-limit testing is recommended at the CoA stage so the bioassay readout is not confounded by contamination unrelated to the test article.
Academic Laboratories
Universities, medical schools, and government research institutes qualifying a reference standard for a method-development or in vivo workflow.
Every release ships with its own batch-specific CoA — identity, purity, and the analytical scope agreed at quote stage, tied to the exact lot you receive.
Review a representative batch CoA before you order, so you can confirm the packet matches what your method or sponsor audit needs.
Supplied strictly as a research reagent to research institutions — not a finished dosage form and not for human administration. Buyer qualification runs at the inquiry stage.
Specifications
Documentation available on request
Regulatory note
Sold for Research Use Only under the receiving laboratory's institutional and jurisdictional regulations. Not a finished dosage form and not labelled for human administration. In vivo research workflows should request endotoxin and microbial-limit testing on the specific lot so the bioassay readout is not confounded by contamination.
Selected literature
Frequently asked questions
C-terminal amidation replaces the free Asn28 acid with an amide, a change of roughly one mass unit, so the identity check is an ESI-MS reading at the theoretical amidated mass, one Da below where the free-acid impurity would appear. Because that offset is small, the measurement has to resolve the amidated species from any residual free-acid form left by incomplete amidation. Confirming the amidated peak dominates matters because the unamidated variant carries substantially lower VPAC1/VPAC2 affinity, so free-acid contamination would blunt receptor-binding readouts.
Native VIP binds VPAC1 and VPAC2 with comparable affinity and does not pharmacologically separate them, so it functions as a non-selective agonist standard rather than a subtype-selective probe. The two receptors are distinct gene products (VIPR1 and VIPR2) with different tissue distributions, and teasing their contributions apart requires engineered selective analogs, such as the VPAC2-selective Bay 55-9837, not native VIP. Used correctly, the native peptide serves as the balanced-affinity reference against which selective analogs are compared, provided its amidated identity is first confirmed by mass spec.
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