Fat cell. Coloured scanning electron micrograph (SEM) of a fat-storing cell (adipocyte, yellow). Almost the entire volume of the fat cell consists of a single lipid (fat or oil) droplet. Fat cells and their supporting connective tissue (blue), make up adipose tissue. Adipose tissue forms an insulating layer under the skin, storing energy in the form of fat created from excess food. Magnification: x700 at 6x7cm size.