Various methods exist for identifying and quantifying lipid unsaturation, including mass spectrometry and Raman spectroscopy. A disadvantage of these existing approaches is the need for sophisticated equipment and software, placing them beyond the means of many laboratories. The iodine value (IV) is a colorimetric unsaturation index
however, it uses iodine monochloride, a hazardous chemical, and considerable amounts of sample. Here, we demonstrate the first use of a miniaturized IV method that requires only milliliter quantities of hazardous chemicals and sample sizes such that it is feasible to assay biological membranes. Briefly, lipids are exposed to iodine monochloride, resulting in the replacement of unsaturated bonds with di-halogenated single bonds. Potassium iodide then reacts with unreacted iodine monochloride forming I