How we test every batch

What it measures

Quantifies the target peptide versus impurities, truncations, and unrelated peaks.

Method

High-performance liquid chromatography (HPLC) with UV detection at the peptide-specific wavelength. The chromatogram is integrated to calculate the area percent of the target peak versus all other detectable peaks.

Why it matters

Impurities and truncated sequences can alter binding affinity, assay reproducibility, and biological readouts in cell culture or biochemical experiments. A purity figure without chromatographic trace data is not sufficient for research reliability.

What it measures

Confirms that the molecular mass matches the sequence declared on the label.

Method

Electrospray ionization mass spectrometry (ESI-MS) or matrix-assisted laser desorption/ionization (MALDI-TOF). The observed mass is compared against the theoretical monoisotopic or average mass of the sequence.

Why it matters

Misidentified, substituted, or degraded peptides can masquerade as the correct compound while producing entirely different experimental results. Mass spec identity is the definitive cross-check against synthesis or sourcing errors.

What it measures

Quantifies bacterial endotoxin load in the finished product.

Method

Limulus amebocyte lysate (LAL) chromogenic endpoint assay, calibrated against USP endotoxin reference standards. Results are reported in endotoxin units per milligram (EU/mg).

Why it matters

Bacterial endotoxins are potent immune stimulants. In cell culture or in vitro assays, even trace endotoxin can confound proliferation, cytokine, and signaling readouts. For reproducible research, endotoxin must be quantified, not assumed.

What it measures

Screens for toxic elemental contamination from synthesis reagents or raw materials.

Method

Inductively coupled plasma mass spectrometry (ICP-MS) scans for lead, arsenic, cadmium, and mercury. Sample preparation includes acid digestion and internal standard correction for matrix effects.

Why it matters

Peptide synthesis uses metal-containing reagents, catalysts, and solvents. Residual heavy metals can alter enzyme kinetics, interfere with metal-sensitive assays, and pose safety concerns during long-term storage and handling.

What it measures

Confirms the absence of viable microorganisms in the sealed finished vial.

Method

Membrane filtration sterility testing per USP <71> or equivalent pharmacopeial method. The filter membrane is cultured in fluid thioglycollate medium and soybean-casein digest medium for the required incubation period.

Why it matters

A sterile product is essential for clean reconstitution and any experiment where microbial contamination could compromise cell cultures, sterile buffers, or assay reagents. Sterility is tested on the finished lyophilised vial, not the raw powder alone.

What it measures

Quantifies total aerobic microbial and yeast/mold counts on raw material prior to final processing.

Method

Total aerobic microbial count (TAMC) and total combined yeasts and molds count (TYMC) by membrane filtration or pour-plate method, following pharmacopeial microbiological enumeration procedures.

Why it matters

Bioburden testing catches upstream process hygiene failures before material reaches the filling and lyophilisation stage. It complements sterility testing by confirming that the starting material was manufactured under adequate microbial control.