Reading a certificate of analysis

A certificate of analysis (COA) is the primary document researchers use to validate peptide identity and quality. Here is how to read the fields you will see on an Ascend Bio Labs COA.

Identity confirmation

Look for **molecular weight** and **sequence confirmation** via LC-MS or similar methods. The observed mass should match the theoretical mass for the labeled compound within method tolerance.

Purity (HPLC)

**Peak area percent** reports the main peptide peak relative to total detected signal. Research-grade material typically targets high purity, but the acceptable threshold may vary by compound and application. Compare against your lab's internal standards.

Water content and appearance

Lyophilized products are reported as a white to off-white powder. Elevated moisture can affect stability; COAs may include Karl Fischer or equivalent data where relevant.

Endotoxin

For applications sensitive to endotoxin contamination, review the **LAL** or equivalent endotoxin result and confirm it meets your experimental requirements.

Batch traceability

The **batch/lot number** on the COA must match the label on the vial you received. If they do not match, contact support before use.

Not a clinical document

COAs support laboratory research workflows. They do not constitute medical advice, prescribing information, or approval for human or veterinary use.