Expression of CD34 in the follicles of fetal scalp

Objective: To observe the expression of CD34 in fetal scalp.Methods: The fetal scalp with follicles was from a fetus (at eight months of gestational age) within 2 h of his death after an abortion due to abnormal development.The tissue was divided into two copies.An equal part was prepared for the frozen sections labeled by CD34 immunofluorescence and observed by laser confocal microscope.Another part was digested by collagenase type Ⅱ for harvest of free hair follicles,which were furtherly treated by trypsin for cells suspension.The hair follicle cells were assayed by flow cytometry.Results: CD34 was mainly expressed in the outer root sheath bugle area of hair follicle under confocal microscopy,a minority was seen in the hair bulb and the basilar part of epidermis.The data from flow cytometry demonstrated that CD34 positive cells accounted for 8.54-13.04 percentages of total isolated follicle cells.Conclusions: Most CD34 positive cells are localized at the bulges of hair follicle which is presumed as the residence of follicle stem cells.The presence of CD34 positive cells in the follicular middle part and lower part around hair bulb,suggests the locations of stem cells and their immediately progenies varied along with the hair cycle.Furthermore,CD34 positive cells equably scatter at the basilar part of epidermis in the fatal scalp.