AbstractThe use of Nile Red to track and stain low density lipoprotein (LDL) and modified LDL in agarose gels was investigated. Lipoproteins were prestained with Nile Red, a fluorescent dye, prior to electrophoresis. After 2 h of electrophoresis, the LDL and modified LDL were visualized using a UV transilluminator with an excitation wavelength of 302 nm. Spectrofluorometric analysis revealed that the Nile Red fluorescence of the stained LDL had an emission maximum of 609 nm. This rapid staining method of LDL and modified LDL can detect as little as 2.5 μg of LDL protein and permits the immediate visualization of these lipoproteins in agarose gels