Wrinkles, dryness and a translucent and fragile appearance are hallmarks of old skin, caused by the natural aging of skin cells. But while most of us can recognize the signs of lost youth when we peer into the mirror each morning, scientists do not have a standardized way to measure the extent of age damage in skin. Now, a group of Taiwanese researchers have used a specialized microscope to peer harmlessly beneath the skin surface to measure natural age-related changes in the sizes of skin cells.
This series of harmonic generation microscopy images shows the skin cells of a 24-year-old subject at increasing depths, ranging from the outermost layer of skin (a) to approximately 300 millionths of a meter deep (f). The magenta areas, generated from third harmonics, show skin cells and their nuclei. The green areas, generated from second harmonics, show fibers made of the protein collagen. (Credit: Biomedical Optics Express)