With all of today’s sophisticated microscopes, you’d think it would be simple to take high-magnification photos of fat—but it’s not. Fat tissue often leaks slippery contents, namely lipids, when it’s thinly sliced for viewing under a microscope. And even when a sample is prepared without leakage, there’s another hurdle: the viscous droplets of lipid contained in the fat cells block light from passing through.
So, it’s good news that one of NIH’s intramural scientists here in Bethesda, MD, has come up with a way to produce high-resolution, 3-D images of fat cells like the one you see above. Not only are these images aesthetically appealing, but they’ll be valuable to efforts to expand our understanding of this essential and much-maligned tissue.
To achieve this feat, Daniela Malide, a staff scientist at our National Heart, Lung, and Blood Institute’s microscopy core, took advantage of a new fluorescent red dye (LipidTox Red) developed to label lipid molecules inside cells. The dye had never been used to stain entire fat cells, but Malide decided to try it on some fat tissue taken from a mouse that had been genetically engineered to make its blood vessels glow green.
After exposing the fat tissue to the dye for 30 minutes, Malide examined it with confocal and two-photon microscopy. And she was stunned by the dramatic results. The dye clung to the lipid molecules, transforming each spherical fat cell into a scarlet orb surrounded by a network of fluorescent green blood vessels. To reveal the 3D architecture of the fat tissue in greater detail, Malide then used a computer to piece together approximately 200 images.
Malide’s work focused on white fat cells, which are among the largest cells in the body, at about 100 microns in diameter. These cells’ best known function is storage of extra calories. And too much of a good thing can be a problem, as our national epidemic of obesity demonstrates. Not only can too much fat make it difficult to move and fit into clothes, it can raise the risk of a wide array of health problems. For example, having too much white fat, especially around the belly, can increase the odds of developing heart disease, diabetes, and certain types of cancer.
Malide’s imaging is currently featured in the Life: Magnified exhibit at Dulles Airport, co-sponsored by NIH. Her work was also recognized as an “image of distinction” at the 2013 Nikon Small World Photomicrography Competition. Malide is delighted by this recognition, because she thinks art is a wonderful way to communicate science and inspire people.
Light Microscopy Core, NHLBI
Application of immunocytochemistry and immunofluorescence techniques to adipose tissue and cell cultures. Malide D. Methods Mol Biol. 2008;456:285-97.
Confocal Microscopy of Adipocytes. Malide D. Methods Mol Biol. 2001;155:53-64.
NIH support: National Heart, Lung, and Blood Institute; National Institute of General Medical Sciences