Constructive improvement of the ultrasonic separation device ADI 1015.

The use of the ultrasonic separation deviceis a very important step in the direction forimproving animal cell bioreactor cultures. However,the normal construction of the ultrasonic separationdevice ADI 1015 has an inherent disadvantage inpumping the cell suspension continuously through thedevice by using a peristaltic pump. The cells aretaken out of the reactor and are transported to theside inlet located below the separation chamber of thedevice. This cycling leads to cell death and aconsiderable reduction of the viable cell density. Themodification of the configuration of the device (nocirculation of the cell suspension through theretention device; during approximately 9 minutescell-free supernatant is extracted; every 9 minute forabout one minute, the volume which is equivalent tothe interior volume of the chamber and the tubingconnecting the device to the reactor, is flushed backin order to return the retained cells back to thereactor) allows cell densities from 10(6) to2.7 x 10(6) c/ml with a viability of at least90% (tested for the shear sensitive insect cell lineHigh Five), whereas the maximal cell densitiesobtained were 0.76 x 10(6) c/ml for the periodof continuous culture and 10(5) c/ml at the end ofthe use of the device in the classical mode.