Clarification of Cell Harvests from Micro Bioreactors

Lab scale clarification of cell harvests is increasingly becoming more challenging as the standard clarification techniques such as centrifugation, tangential flow filtration (TFF) and depth filtration are not easily adaptable to micro bioreactors which require multiple processing of small volumes of cell harvests, typically 50 mL. Centrifugation may damage the shear sensitive mammalian cells and not only release undesirable intra cellular proteins and DNA into the broth but also submicron particles which are difficult to remove. TFF systems require long setup time and are prohibitively expensive for lab scale volumes. Depth filters on the other hand necessitate monitoring of differential pressures and sometimes allow passage of cell debris and other fine particulate which tend to choke the downstream 0.2µm sterilizing grade filters. Also, these require large pre-use flush volumes to remove inherent extractables owing to their cellulosic matrix with inorganic filter aids such as diatomaceous earth or perlite. Continue reading “Clarification of Cell Harvests from Micro Bioreactors”

How to clarify cell harvests without centrifugation in the lab?

Bio-pharmaceutical industry is involved in development and manufacture of therapeutic drug proteins and monoclonal antibiotics using mammalian cell expression systems, a vital and constantly developing technology.

Cultured cells from mammalian cell expression systems, ranging from a few mL to a few liters in shaker flasks, cell factories and small bioreactors to thousands of liters in large bioreactors, deliver extracellular protein and need to be harvested and clarified for downstream processing to obtain the purified protein of interest. Cell culture clarification is necessary to protect highly sensitive and expensive downstream processes such as diafiltration, ultrafiltration and protein chromatography, and is a challenging task as it contains whole cells, cell debris from dead cells as well a whole gamut of proteins from the cellular activity.

Continue reading “How to clarify cell harvests without centrifugation in the lab?”