Lipid A double bond position determination using ozone and laser-induced dissociation

Ozone coupled with tandem MS is a traditional tool to assign double bond position in lipids. However, few studies were reported on the use of ozone for double bond determination of bacterial lipids. Most MS-based double bond localization methods used in bacterial lipidomics focused on low molecular weight phospholipids, but never tested for assigning double bond position in complex glycolipids such as Lipid A. Here, we present a simple approach to identify unsaturated lipid A double bond position using on-MALDI plate ozone treatment of intact Lipid A.