COA Certified · Every Batch Tested•Same-Day Shipping on Orders by 2PM EST•USA Sourced · USA Shipped•Free Shipping on Orders Over $300•4.9/5 from 2,400+ Verified Researchers•
COA Certified · Every Batch Tested•Same-Day Shipping on Orders by 2PM EST•USA Sourced · USA Shipped•Free Shipping on Orders Over $300•4.9/5 from 2,400+ Verified Researchers•
Quality Peptide USAQuality Peptide USA
HomeResearchEpithalon
Lab Testing & Purity

Epithalon Lab Testing & Purity Standards: HPLC, MS & Endotoxin

3 min read•Published 2025-01-22•Quality Peptide USA Research

Epithalon (also written Epitalon) is a synthetic tetrapeptide bioregulator modeled on a peptide fragment of the natural pineal hormone epithalamin. It is widely studied in longevity research for influence on telomerase activity, circadian regulation, and cellular senescence.. This guide covers lab testing & purity for Epithalon — written for laboratory researchers sourcing US-synthesized peptides from Quality Peptide USA.

Purity by Reverse-Phase HPLC

Every batch of Epithalon is analyzed by reverse-phase HPLC using a C18 stationary phase and a water/acetonitrile gradient with 0.1% TFA. The release specification is ≥ 99% purity by area-under-curve at 220 nm. The chromatogram is included in the full certificate of analysis PDF available on the Epithalon product page.

Identity by Mass Spectrometry

Epithalon identity is confirmed by electrospray ionization (ESI) or MALDI-TOF mass spectrometry. The observed molecular ion is compared against the calculated mass (≈ 390.35 g/mol) and must match within 1 Da to pass release. Sequence-level confirmation is performed on representative lots through MS/MS fragmentation.

Endotoxin and Bioburden

Every batch is screened with the Limulus Amebocyte Lysate (LAL) assay. Release specification: < 0.10 EU/mg. Bioburden is verified by membrane filtration with target < 1 CFU per vial. These thresholds matter for cell-culture work where endotoxin contamination confounds inflammatory and proliferation readouts.

Water Content and Residual Solvents

Karl Fischer titration verifies water content below 5%, ensuring the lyophilized cake is fully dry. Residual organic solvent screening (gas chromatography) confirms acetonitrile and TFA residuals are within USP <467> Class 3 limits. This is one of the most overlooked QC steps when sourcing peptides from overseas suppliers — but it directly influences downstream cell viability.

Research Use Only

All content is for laboratory and in-vitro research contexts only. Not intended to diagnose, treat, or prevent any condition. Not for human or veterinary consumption.

EpithalonEpithalon researchEpithalon lab testing & purityEpithalon for salebuy EpithalonEpithalon US synthesizedEpithalon American peptidesEpithalon certificate of analysisresearch peptidesQuality Peptide USA