Technology | Peptide Labs Health

Process Steps

Crude Analysis

The crude peptide mixture is first analyzed by analytical RP-HPLC (C18 column, acetonitrile/water gradient with 0.1% TFA) and ESI-MS to assess initial purity, identify the target peak, and characterize major impurities.

Method Development

Chromatographic conditions are optimized for each peptide based on its hydrophobicity, charge, and impurity profile. Gradient slope, column chemistry (C4, C8, C18), mobile phase composition, and temperature are systematically varied to achieve baseline resolution.

Preparative Purification

The crude peptide is loaded onto a preparative RP-HPLC column and separated using the optimized gradient. Target fractions are collected by UV-triggered fraction collection at 214 nm, maximizing recovery while maintaining stringent purity cutoffs.

Fraction Analysis

Each collected fraction is analyzed by analytical HPLC and mass spectrometry. Only fractions meeting the target purity specification (typically greater than 95%, 98%, or 99% depending on the product grade) are pooled for the final product.

Lyophilization

Pooled fractions are frozen and lyophilized (freeze-dried) to yield a stable, fluffy white powder. Lyophilized peptides are weighed, aliquoted, and stored under nitrogen at -20 degrees Celsius to ensure long-term stability.

Quality Documentation

A comprehensive Certificate of Analysis is generated for each lot, including analytical HPLC chromatograms, mass spectrometry data, amino acid analysis (for select products), peptide content determination, and appearance assessment.

Overview

High-Performance Liquid Chromatography (HPLC) is the gold standard for peptide purification and quality analysis. At Peptide Labs Health, our purification laboratory is equipped with a fleet of analytical and preparative HPLC systems from leading manufacturers, configured with UV-Vis, fluorescence, and evaporative light scattering detectors. Our systems operate with column sizes ranging from 4.6 mm analytical columns to 50 mm preparative columns, enabling purification at scales from micrograms to multi-gram quantities.

Reversed-phase HPLC (RP-HPLC) exploits differences in the hydrophobicity of peptide species to achieve separation. The crude peptide mixture is dissolved in an aqueous mobile phase and loaded onto a column packed with silica particles bonded with hydrophobic C18, C8, or C4 alkyl chains. A gradient of increasing organic solvent (typically acetonitrile) elutes peptide species in order of increasing hydrophobicity, with the full-length target peptide typically resolving as a discrete peak well-separated from deletion sequences and other impurities.

Advanced Techniques

For particularly challenging separations, we employ orthogonal purification strategies that combine RP-HPLC with ion-exchange chromatography (IEX) or size-exclusion chromatography (SEC). This multi-dimensional approach enables the resolution of closely related impurities — such as single-residue deletion sequences or deamidation products — that may co-elute under standard reversed-phase conditions. We also utilize high-temperature HPLC (up to 80 degrees Celsius) to improve peak shape and resolution for hydrophobic and aggregation-prone peptides.

Our analytical capabilities extend beyond HPLC to include electrospray ionization mass spectrometry (ESI-MS), MALDI-TOF mass spectrometry, amino acid analysis (AAA), and capillary electrophoresis. This comprehensive analytical toolkit ensures that every Peptide Labs Health product meets or exceeds its stated specifications, providing researchers with the confidence to build their work on a foundation of rigorously characterized materials.