Updated project metadata. Mitochondria are the provider of cellular energy from aerobic respiration in all tissues. However, only brown adipose tissue (BAT) mitochondria are able to convert chemical energy in the form triglycerides into heat (thermogenesis). To ask if cellular respiration or thermogenic function require a specific lipidomic environment, we investigated the lipid species composition of brown adipose tissue mitochondria, and compared it those purified from liver, skeletal muscle and white adipose tissue. We emplyed mass spectrometry-based proteomics to evalaute the purity of the mitochondia fractions isolated from murine BAT and liver tissue by differential centrifugation, by comparison of its full proteome with endoplasmatic reticulum, mitochondrial-associated membrane, and mitochondria fractions isolated by density gradient centrifugation.