H.M.D.R. Herath

This article describes possible sources of error that may contribute to significant inaccuracy in peptide assay methods: The fi ltration material (cellulose) used in sample clean up and the vial material (glass and plastic) used in LC analysis. This study is based on ?-endorphin but has relevance for most peptide assays.

Likely sources of error are filtration and vial materials.