Experts Sheds The Light On Melanin And It’s Architecture

Pennsylvania: Penn State College of Medicine researchers recently announced the development of a new imaging process that scientists could use to portray every melanin cell in 3D view.

Melanin is a pigment, ranging from brown to black, that gives most living creatures darker hues. In zebrafish, that’s its characteristic stripes, and in humans, it’s dark skin, hair and eyes. Melanin-containing cells are often the hardest to view due to the pigment blocking off most light. Researchers turned to X-ray imaging to counteract this, which can pass through visually opaque matter like melanin. Three-dimensional interpretation can prove fruitful for scientists and analysts alike when researching skin and hair pigmentation and ailments such as albinism or melanomas. This imaging helps determine the architecture, content and location of pigment cells in better clarity.

Dr Keith Cheng, Professor of Pathology, Pharmacology and Biochemistry and Molecular Biology, established “X-ray histotomography” — CT imaging at the cellular level, as a way to observe the 3D design of cells in samples even more transparently than ever before. Spencer Katz, a student on Cheng’s team, has adapted this micro-CT technique to target melanin in zebrafish specifically.

Micro-CT, like human CT, utilizes X-rays taken at multiple different angles to add or recreate 3D illustrations of the initial sample. The sample size is usually smaller in Micro-CT and the resolution, in this particular case, is 2000 times higher. Silver was applied to tint the melanin, which helped determine the location and melanin density.

The melanin-containing cells, called melanocytes, and their positions were then easily compounded in 3D. Moreover, they got quantifiable numbers of their melanin content, which helped compare normal and mutant fish.

In the future, the Cheng Lab will continue to work on new marking and visual approaches for expanding how histotomography can be used. This study represents how whole-body, 3D computational exploration of biological matter can be achieved using micro-CT to offer a more complex understanding of genetic function.

This research was sustained by the National Institutes of Health, the Pennsylvania Department of Health Tobacco CURE Funds, the Jake Gittlen Laboratories for Cancer Research, Penn State Huck Institutes of the Life Sciences and Penn State Institute Computational and Data Sciences.