Leukocytes and other cells show an enhanced intensity of mobile lipid in their 1 H NMR spectra under a variety of conditions include stimulation, which has recently been shown to involve detergent-resistant, plasma membranedomains (DRMs)oftencalled there ismuchspeculationsurrounding theoriginof cellularNMR-visible lipid, we analysed subcellular fractions, including DRMs, by NMR spectroscopy.