title: How long can hair follicle units be preserved at 0 and 4 degrees C for delayed transplant?
abstract: BACKGROUND
  Preservation of hair follicle units for the purpose of delayed transplant will help us graft thousands of hair grafts at one session, even in a clinic with fewer assistants and less equipment.
  
  
  OBJECTIVE
  This study was undertaken to evaluate and compare the viability of hair follicle units preserved at 0 and 4 degrees C for various periods.
  
  
  METHODS
  Cell cultures and transplant of hair follicle units into athymic mice were performed.
  
  
  RESULTS
  Outer root sheath cells could be cultivated in 96% (0 degrees C group) and 92% (4 degrees C group) of the hair follicles after 24 hours of preservation, whereas 85% (0 degrees C group) and 79% (4 degrees C group) of the follicles implanted into the mice regrew well after the same period of preservation. Then, in both the 0 degrees C and the 4 degrees C group, these rates decreased significantly with length of preservation in cell cultures and mice transplant; however, 0 degrees C seems better than 4 degrees C for preservation of grafts (p<.05).
  
  
  CONCLUSIONS
  Grafts are better preserved at 0 degrees C instead of 4 degrees C. When delayed transplant is an option, it should be completed within 24 hours and no later than 48 hours.
authors.affiliation: Department of Dermatologic Surgery, Institute of Dermatology, Peking Union Medical College and Chinese Academy of Medical Sciences, Nanjing, PR China. qianjiange@sohu.com
authors.forename: Qian
authors.initials: Q
authors.lastname: Jiange
authors.forename: Li
authors.initials: L
authors.lastname: Wenzhong
authors.forename: Zhang
authors.initials: Z
authors.lastname: Guocheng
authors.forename: Yan
authors.initials: Y
authors.lastname: Liangbin
authors.forename: Sun
authors.initials: S
authors.lastname: Wei
mesh_terms: D000328:Adult; D000818:Animals; D018929:Cell Culture Techniques; D002470:Cell Survival; D015925:Cryopreservation / Q000379:methods*; D018859:Hair Follicle / Q000502:physiology* / Q000637:transplantation*; D006801:Humans; D051379:Mice; D008875:Middle Aged; D013997:Time Factors