According to pharmacopoeia 8, section 5.14 and 5.2.3; In viral vector production, some tests must be done as in-process tests after cell harvest for control cells (cells at or beyond the doubling level used for production), some tests like as morphology, Tests for extraneous agents (Fungal, bacterial and mycoplasma contamination) are easy to perform, but other tests like electron microscopy, tests in animal and eggs, Identification Tests and co-culture Tests are too time-consuming and costly; so is it obligatory to all these tests for each lot? can we do these tests for 3 batches and after process validation and obtaining consistent data, we refer to our previous data?