What tests have been used and what is the sensitivity 
of the tests? 
(b) If a virus, how is it prepared from the DNA construct? In 
what cell is the virus grown (any special features)? What 
medium and serum are used? How is the virus purified? What 
is its structure and purity? What steps are being taken 
(and assays used with their sensitivity) to detect and 
eliminate any contaminating materials (for example, VL30 
RNA, other nucleic acids, or proteins) or contaminating 
viruses or other organisms in the cells or serum used 
for preparation of the virus stock? 
(c) If co-cultivation is employed, what kinds of cells are 
being used for co-cultivation? What steps are being 
taken (and assays used with their sensitivity) to detect 
and eliminate any contaminating materials? Specifically, 
what tests are being done to assess the material to be 
returned to the patient for the presence of live or killed 
donor cells or other non-vector materials (for exanple, 
VL30 sequences) originating from those cells? 
(d) If methods other than those covered by (a)-(c) are used 
to introduce new genetic information into target cells, 
what steps are being taken to detect and eliminate any 
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