NBD PtdIns(4 5)P2 C16 is an analog of PItdIns(4 5)P2 (PIP2) labeled with NBD on the sn-1 acyl chain. Phosphoinositides (PIPns) are minor components of cellular membranes but are integral signaling molecules for cellular communication. Phosphatidylinositol 4 5-bisphosphate (PIP2) has been shown to play a central role in a variety of cellular functions. Amongst its many functions PIP2 is a substrate for Phospholipase C-coupled G-protein pathways involved in intracellular calcium release in several tissues. It is also a substrate for class I phosphoinositide 3-kinase (PI3-K) forming PI(3 4 5)P3.