OEX_Sijie_2112100934

We obtained discarded human scalp skin samples from plastic surgery and isolated HFs from them by dispase digestion followed by individually pulling the HFs out of dermis. The vast majority of the hsHFs isolated by this method displayed elongated shapes resembling growth phase (anagen). Closer examination showed that no sebaceous gland (SG), interfollicular epidermis (IFE) or dermis was attached to these isolated hsHFs. Scalp samples were collected from Chinese females at age 18 (F18, predominantly black hair), age 31 (F31, grizzled hair), age 59 (F59, predominantly black hair) and age 62 (F62, grizzled hair) respectively. The hsHFs from F18 and F59 black hair samples were collected and sequenced directly. The hsHFs were further sorted into black hsHFs (F31B or F62B) and white hsHFs (F31W or F62W) and sequenced respectively.