صابر نصیری
علیرضا اربابی
اشرف محمدی
ایران یوسفی
زهره حمزه لو
علی ساسانی

It,s necessary to do a deep regearch to determine optimum time to yield the best.. harvest of Measele virus vaccine. Intentionaly Monalayer chick embrio fibreblast cell provided for and a detetminared quantity of virus inoculated to . As virus is as absolute parasit absorbed by receplors arid little by little i inter to the cell and being increased . Harvesting time usually begins about 72-96 hours after inoculation or after appearane of cyto pathic effect (CPE) ,and goes on per 24 hours on the condition that cells resist and do not detach from the fluid of surface of the bottle .Harvested series titred separatly . Titve increasing in a particular time confirm the optimum in harvesting ,that is very. important in production of MEASL+ES vaccine.