In order to compare the survival and growth of olfactory ensheathing cells (OECs) of 80% and 50% purities in vitro,and to present the evidence for the optimal purity of OECs for the transplantation,OECs of adult SD rats were isolated,cultured,purified and mixed for a purity of approximate 80% or 50% with attached fibroblasts. Mixed cells were cultured for one or three days. All the cultured cells were stained with anti-p75 immunocytochemistry to verify the initial and subsequent numbers and purities of OECs...