Melanoma cells imaged using CARS microscopy to visualize pheomelanin (top) and SFA microscopy to image total melanin content (bottom).
People with light colored skin, and particularly orange tinted redheads, have high levels of pheomelanin, a type of melanin, in their skin. It is correlated with amelanotic melanoma, a nasty skin cancer that’s difficult not only to treat, but to detect in the first place. This is because pheomelanin within amelanotic melanomas blends in with healthy skin, making it difficult to spot, unlike the much darker eumelanin that’s related to the majority of melanomas.
At the Massachusetts General Hospital’s Wellman Center for Photomedicine, researchers have devised a new technique for visualizing pheomelanin within the skin, potentially helping to identify a deadly cancer early in its development. The details of the research are to be presented next month at The Optical Society’s Biophotonics Congress: Optics in the Life Sciences in San Diego, CA.
What we do know is that the technique relies on coherent anti-Stokes Raman Scatterings (CARS) microscopy, a version of commonly used Raman spectroscopy that can identify the chemical composition of prepared samples. CARS involves two lasers that are used to resonate target molecules to detect their presence at high resolution over a wide sample area.
As part of their research, the team identified another related method, called sum-frequency absorption (SFA) microscopy, as being able to spot eumelanin. Using both CARS and SFA can provide images of the distribution of the two types of melanin, which are often produces simultaneously in many melanoma patients.
Via: The Optical Society…