Briefly, heparinized
blood sample (0.5 ml), was obtained from each female
and was placed in a sterile cultured tube containing 7 ml of
RPMI 1640 medium, supplemented with fetal calf serum
(1.0 ml), antibiotic–antimycotic mixture (1.0 ml) and phytohaemagglutinin-
M (0.1 ml).