Used as a stable isotope-labeled internal standard in mass spectrometry-based lipidomics to accurately quantify phosphatidylserine species in biological samples. Its deuterated chains allow clear distinction from endogenous lipids, minimizing interference from matrix effects. Commonly applied in studies of cell membrane dynamics, apoptosis, and neurological disorders where phosphatidylserine plays a key signaling role. Also employed in tracer experiments to monitor lipid metabolism pathways and in the development of lipid-based pharmaceutical formulations requiring precise analytical validation.