Quantitative analysis of hair follicles using optical coherence microscopy and digital staining

Observation of hair follicles is a crucial indicator for monitoring various physiological and pathological conditions. It provides valuable diagnostic information and helps develop new treatments in areas such as hair loss, circadian rhythms, skin diseases, and aging. Histopathological methods are currently considered the gold standard for examining hair follicle structure, but they face inherent technical limitations when attempting to offer dynamic and quantified information. In this study, we introduce a protocol to investigate hair follicles using a label-free multi-scale optical imaging device that combines OCT and OCM functionalities. This approach dynamically monitors three-dimensional morphological changes of hair follicles with OCT and rapidly quantifies them with high-resolution OCM when histopathological analysis is required. A unique feature of this study is the ability to obtain tissue pathology information within one hour, along with the advantage of quantitatively analyzing hair follicles using OCM and digital staining. Furthermore, the integration of in vivo/ex vivo imaging enables the acquisition of functional and structural information about hair follicles that is not revealed by traditional histopathological methods. The proposed method is expected to have novel applications beyond hair follicle observation, extending to various fields of histopathology. It is particularly useful in situations where rapid histopathological information is needed, such as in surgical settings.