Maternal blood samples (sera) were tested for: HIV (Abbott Laboratories, Abbott Park IL, USA) hepatitis A, B and C (Abbott); HTLVI (Abbott); VDRL (Baxter Agglutination Slide Test and reflex FTA), and cytomegalovirus (Quest, Oxnard CA). Women with a history of genital herpes, cancer, asthma, lupus, rheumatoid arthritis, allergies, vasculitis of autoimmune origin, and drug abuse were excluded. Gestation was determined according to Carnegie stages. Fetal tissue was harvested at the sixth week of gestation after elective abortion. Fetal brain was dissected, minced and triturated to a single cell suspension. Cells were cultured in flasks incubated at 37°C under hypoxic conditions (5% O2 and 5% CO2) through 4 doublings. At the second doubling (D2) cell culture was tested for sterility (USP <71>) and at D4 culture was karyotyped and PCR tested for presence of adventitious agents: HTLV-1, HTLV-2, HIV-1 (A, B, D, F, H, N), hepatitis A, B and C, T. p. pallidum, CMV, HSV-1, HSV-2, HPV. Cells were then transferred to a closed bioreactor system (GE WAVE Bioreactor 2/10 System, Uppsala SWE), operating under the same physical and chemical conditions. The bioreactor was used to create the Master Cell Bank (MCB), which was harvested, tested, characterized and rate-control cryopreserved after a total of seven doublings (D7).