Phosphatidylethanolamine (PE) is the second most abundant phospholipid in mammalian cells. PE comprises about 15–25% of the total lipid in mammalian cells. It is enriched in the inner leaflet of membranes, and it is especially abundant in the inner mitochondrial membrane. phosphatidylethanolamine assay https://lipidomics.creative-proteomics.com/phosphatidylethanolamine.htm