Abstract: The invention relates to a method of removing an agent from a suspension of cells using a semi-permeable membrane. In one aspect of the invention, the cells are used to bioprocess a biological fluid after removal of the agent.

Abstract: The invention is based in part on the observation that significant portions of porcine livers appear to remain intact after perfusion by standard methods, suggesting that the perfusion procedures employed do not result in complete enzymatic digestion. Recovery of cells is therefore substantially lower than would be possible if the organs were thoroughly digested. It is found that increased perfusion flow rate, occlusion of at least one major blood vessel leading out of the organ, increased enzymatic digestion time, and vigorous tissue dissociation techniques can be combined to afford a uniquely high yield of viable cells.

Abstract: The invention features a method of processing cryopreserved cells by thawing and equilibrating the cells at warm temperatures (e.g., between 30.degree. C. and 43.degree. C). Either the cell suspension in the cryoprotective medium is thawed to a temperature between 35.degree. C. and 43.degree. C. or the cryoprotective medium is equilibrated with a culture medium at a temperature between 35.degree. C. and 43.degree. C., or both steps are carried out at the warm temperatures. By thawing and equilibrating the cryopreserved cells at warm temperatures, the viability, (especially after 3 hours of culture), and metabolic activity (i.e., diazepam metabolism) of the cells can be improved over traditional cold cell processing (i.e., at temperatures of between 2.degree. C. and 8.degree. C.).