Autofluorescence in the Stem Cell Region of the Hair Follicle Bulge

The study observed autofluorescence in the stem cell region of the hair follicle bulge, specifically in the peri-nuclear cytoplasm of bulge keratinocytes, during fluorescent antibody studies. This autofluorescence was consistent across various preparation methods and fixatives and was significantly reduced by a reducing agent, indicating it might be due to high levels of flavin- and NAD-related compounds. These findings suggested that the autofluorescence reflected the unique metabolic status of quiescent stem cells and emphasized the importance of considering autofluorescence in immunofluorescent studies to prevent misinterpretation. Additionally, the study proposed the potential use of autofluorescence in cell-sorting protocols to isolate human bulge cells.