RELi protocol: Optimization for protein extraction from white, brown and beige adipose tissues

Abstract Global obesity rates have reached pandemic proportions, increasing the risk of metabolic complications for hundreds of millions of individuals worldwide. Gaining insight on adipose tissuebiology and understanding how fat padsbehave during obesity is critical to investigate metabolic syndromes. Elucidation of cellular signaling pathways engaged by adipose tissueboth in health and disease requires standardized protocols for protein extraction that yield consistently pure samples. A recurrent problem of currently available protocols is lipid or detergent contamination in extracted protein samples, which renders protein quantification inaccurate and, as a consequence, consistency and reproducibility of protein loading become unreliable. To overcome this problem, we improved the process of adipose tissueprotein extraction by improving tissue lysis and decreasing lipid contamination. Here we describe the Removal of Excess Lipids (RELi) protocol to obtain increased yields of total proteins extracted from adipose tissue. The RELi protocol allows accurate and reproducible adipose tissuesample preparation for Western blot analysis and other investigative techniques requiring adipose tissue-derived proteins.