3D RECONSTRUCTION OF HUMAN HAIR BY CONFOCAL MICROSCOPY

Confocal microscopy is a highly original, non-destructive method for observing objects in three dimensions and in their natural environment. As such, it is well suited to studies of human hair. The tandem-scanning reflected-light microscope was used to study the hair surface in its natural environment, which included sweat and sebum. Micrometric measurements assessed the effects of classical treatments (permanent waving and bleaching), swelling in water and urea solution, and stretching. A confocal laser scanning microscope was used to reconstruct a volume of hair shaft. The internal structures (cortex and medulla) were contrasted using a fluorescent marker (rhodamin) and could be observed in both longitudinal and transverse optical sections at all levels. Our results demonstrate the value of confocal microscopy in describing hair structure and the effects of treatments on the cuticle. Methods based on classical optical and electron microscopy are far more complex and time-consuming than confocal microscopy, which represents an extremely promising technique for cosmetic research.