Lipids (2016) 51:497–504 DOI 10.1007/s11745-016-4134-0 1 3 METHODS The Use of Kits in the Analysis of Tissue Lipids Requires Validation T. Rider 1 · R. C. LeBoeuf 2 · Patrick Tso 3 · R. J. Jandacek 3 Received: 7 December 2015 / Accepted: 16 February 2016 / Published online: 7 March 2016 © AOCS 2016 Introduction The measurement of the concentration of cholesterol, phospholipids, and triacylglycerols in tissues is frequently used to understand the metabolic effects of diet, pharma- ceuticals, and genetics. In serum these classes of lipids are readily analyzed by kits designed for concentrations that are seen in blood. These kits, which utilize enzymatic reac- tions, are convenient, fast, and efficient. Although these kits are designed specifically for use in blood analyses, they are used in the measurement of lipids in biological samples other than serum (see, e.g., [1–4]). As we demonstrate and discuss below, it may not be assumed that the use of these kits for analyses of these lipids in tissues is validated for measurement of lipids in all tissues. There are several reasons that the kits may not be applicable for use in all tissues. A potential source of error in using the kits in tissue lipid analysis results from the need to extract lipids from tissues to isolate them for analy- sis. The dissolution/suspension of extracted lipid in a sol- vent system that is compatible with the kit is then needed. One may not assume that the uptake of lipid by this solu- tion/suspension is complete since the extracted lipid may exceed the capacity of the solvent system. Another poten- tial source of error is the measurement of concentrations of lipids that fall outside of the range found in serum, for which the kits are designed. Also, in the case of cholesterol measurement, the presence of triacylglycerol at relatively high levels may interfere with the reactions and measure- ment unless prior to analysis the sterols are isolated as the non-saponifiable fraction of the lipids. The purpose of this paper is to present evidence that the validity of the kits for the analysis of tissue lipids may not be assumed. We have not attempted to determine conditions Abstract The ready availability and ease of use of kits for the measurement of serum lipids has greatly facilitated these measurements. In many cases it would be convenient to use these kits in the determination of lipid concentrations in tissues. The successful application of serum kits in tissue analysis requires that two important issues be considered. First, the solvent system for the extraction of the lipids and the solvent used for analysis by the kit must be compat- ible with the reactions in the kit. Second, the concentration range in the analyzed solution must be within the range for which the kit is used. We report here that lipids in liver and adipose tissues may be significantly underestimated by the use of some kits. We recommend that the use of kits for tis- sue analysis of lipids be validated for the specific analysis. Keywords Analytical biochemistry · Lipid analysis · Phospholipid analysis · Triglyceride analysis Abbreviations NIH National Institutes of Health NIDDK National Institute of Diabetes and Digestion and Kidney Disease * Patrick Tso Patrick.Tso@uc.edu 1 Department of Cancer Biology, University of Cincinnati, Cincinnati, USA 2 Department of Medicine, University of Washington, Seattle, USA 3 Department of Pathology and Laboratory Medicine, University of Cincinnati, Cincinnati, USA