A method for producing recombinant adeno-associated virus in the absence of contaminating
helper virus or wild-type virus involves culturing a mammalian host cell containing
a transgene flanked by adeno-associated virus (AAV) inverse terminal repeats and
under the control of regulatory sequences directing expression thereof, an AAV
rep sequence and an AAV cap sequence under the control of regulatory sequences
directing expression thereof, and the minimum adenovirus DNA required to express
an E1a gene product, an E1b gene product and an E2a gene product, and isolating
therefrom a recombinant AAV which expresses the transgene in the absence of contaminating
helper virus or wildtype AAV. This method obviates a subsequent purification step
to purify rAAV from contaminating virus. Also provided are various embodiments
of the host cell.