Abstract: This invention is directed to a continuous process for producing viral particles by providing in a perfused growth medium a population of viable virally infected non-lytic cells, and removing medium containing said cells at a rate to maintain the steady-state log-phase growth of cells remaining in the perfused growth medium. The invention is also directed to a process for purifying retroviral particles by passing a solution comprising the retroviral particles and contaminants through an anion exchange resin, and eluting the retroviral particles from the resin. The preferred exchange resin is a tentacle anion exchange resin.

Abstract: Recovery of the 52/48 kDa tryptic fragment of vWF or peptide subfragments thereof produced in the form of inclusion bodies from recombinant host cells is carried out by providing a washed recombinant host cell suspension, adding a detergent and subjecting the cells to mechanical disruption. A second detergent is added, followed by another mechanical disruption and centrifugation to a pellet. The pellet is resuspended in a buffer and subjected to another mechanical disruption. Inclusion bodies are washed, resuspended and then recovered. In addition, endotoxins and DNA are removed from inclusion bodies containing the 52/48 kDa tryptic fragment of vWF or peptide subfragments thereof by mechanically disrupting the inclusion bodies in an aqueous buffer containing a detergent. A washed pellet is formed from these mechanically disrupted inclusion bodies and dissolved in a denaturant.