LYSIS-FREE SEPARATION OF HYBRIDOMA CELLS BY CONTINUOUS DISC STACK CENTRIFUGATION

The non-destructive removal of hybridoma cells from fermentation broth with an improved disc stack centrifuge (CSA1, Westfalia Separator AG, Oelde, Germany) was investigated. The centrifuge was equipped with a hydrohermetic feed system, which allowed a gentle, shearless accelerat ion of the cells inside the bowl. No significant cell damage was obser ved during the separation of hybridoma cells from repeated batch ferme ntation in 100 liter scale. In the clarified liquid phase there was no increase in Lactate-Dehydrogenase (LDH) activity. Consequently, there was no increased exposure of the product to intracellular components. Due to continuous operation with a periodic and automatic discharge o f sediment, a high throughput was achieved without any considerable lo ss of product. The clarification for mammalian cells was in the range of 99% to 99.9%, depending on the operating conditions. The content of cell debris and other small particles decreased about 30 to 50%, depe nding on the particle load in the feed stream. The centrifuge was full y contained; cleaning and sterilizing in place possible. Therefore, th e device could be integrated easily into the fermentation process.