Adipose tissues play critical roles in whole-body homeostasis, including storage and release of energy in response to local and global needs, thermoregulation, and secretion of adipokines to regulate energy balance, metabolism and immune responses1,2. Adipocytes are distributed throughout the body in discrete depots, and in some cases serve specialized roles within their microenvironments3,4,5. Historically, the study of adipose tissue has centered on white adipose tissue (WAT), and its role in maintaining energy homeostasis. Most adipocytes are distributed throughout the body in subcutaneous and visceral WAT depots. The characteristics of these depots are important for differential susceptibility to metabolic diseases. Subcutaneous adipocytes, located beneath the skin, have been associated with protective metabolic effects5. Visceral adipocytes, which surround the vital organs and are contained within the gonadal, perirenal, retroperitoneal, omental and pericardial depots, are commonly linked to metabolic disorders, including type 2 diabetes and cardiovascular disease2. Brown adipose tissues (BAT) have also been studied extensively. Brown and brown-like adipocytes express uncoupling protein 1 (UCP1) and play important roles in adaptive thermogenesis and glucose homeostasis6,7. Classical brown adipocytes are contained in the interscapular BAT depot8. Clusters of brown adipocytes are also found in other locations, including supraclavicular, infra/subscapular, cervical, paravertebral and periaortic depots8,9.
In addition to their location in major WAT and BAT depots, adipocytes exist in discrete niches throughout the body4, where they may perform specialized functions within their respective microenvironments. For example, bone marrow adipose tissue (BMAT) serves as a lipid reservoir, is a major source of circulating adiponectin, and closely interacts with osteoblasts, osteoclasts, and hematopoietic cells10,11. Dermal adipocytes contribute to widespread processes, including wound healing, immune response, thermoregulation, and hair follicle growth12,13. Further, epicardial adipocytes may produce several adipokines and chemokines that exert local and systemic effects on the development and progression of coronary artery disease14. Expansion of inter/intramuscular WAT has been positively correlated with increased adiposity, systemic insulin resistance, and decreased muscular strength and mobility15. In addition, popliteal adipocytes serve as a lipid reservoir for lymphatic expansion during infection16. While the specific roles of different articular depots are generally unknown, the Hoffa depot (infrapatellar) within the knee is now thought to contribute to pathologies, including anterior knee pain and osteoarthritis17.
Whereas regional differences in adipocyte character and function are under intense study, the field is currently limited by the lack of a standardized protocol for the identification and dissection of diverse mouse depots. Previously published methods have typically described the isolation of one or two specific depots and lack the level of detail required for uniform excision18,19. The protocol described in this manuscript provides a comprehensive guide for the specific anatomic locations and isolation steps of many different mouse adipose depots. Although WAT depots are the primary focus of this manuscript, the excision of interscapular BAT is also described in detail. Adipose tissues excised using this protocol can be used for a wide variety of experimental endpoints, including explant studies, histology, and gene expression analyses.
The goal of this manuscript is to provide investigators with a detailed protocol to clearly and precisely identify and isolate both prominent and less-studied mouse adipose depots (Figure 1). This resource will facilitate a more complete investigation of the developmental, molecular, and functional characteristics of adipocytes within diverse niches.

Figure 1: Schematic depiction of mouse adipose depots dissected in this protocol. This image has been adapted from Bagchi et al., 20184. Please click here to view a larger version of this figure.