There are several common methods to detect triglycerides and measure their metabolism in biological samples:
Various inexpensive stains can be used to assess lipid levels in tissue or cell culture samples (e.g., Oil Red O, BODIPY® dye). Staining can be visualized by microscopy, and the progression of lipolysis or lipogenesis can be inferred. However, staining protocols are lengthy, with multiple wash steps, and are not amenable to high-throughput applications. In addition, it is not possible to distinguish between triglycerides and other neutral lipid species with this method.
Colorimetric and Fluorometric Plate-Based Assays
These microplate-based detection kits use a cocktail of enzymes to convert triglycerides or glycerol into a detectable colorimetric or fluorescent signal. These assays can be used to quantitate metabolism and are compatible with a wide variety of sample types. However, they have a limited linear range and may not be sensitive enough to detect physiologically relevant changes in lipid levels. In addition, sample preparation can require organic extraction, which uses toxic solvents under extreme temperature conditions and requires centrifugation.
Spectrometric methods can be used to give a complete picture of the “lipidome”—all the lipid species present in a biological sample. These experiments generate large quantitative data sets, which can be used to characterize lipid metabolism processes. However, mass spectrometry is expensive and requires specialized instrumentation and technical expertise. Such large, untargeted data sets are time-consuming to analyze and may go beyond the scope of your needs.