Tangential flow filtration (TFF) microfiltration has been used as one of the choices for clarification of mammalian cell or microbial cell culture in the biopharmaceutical industry. Unlike the ultrafiltration process for protein concentration and the diafiltration application where the feed solution is relatively clean (free of colloids or larger particles after the clarification/purification process), the microfiltration process needs to handle a rather high-fouling feed stream such as cells, cell debris, colloids, etc. In a previously published article, we discussed that a TFF microfiltration step is limited by a maximum throughput or capacity obtainable under a given set of operating conditions. Some distinct microfiltration characteristics, such as critical permeate flux, permeate flux control, and maximum throughput were explained in that article…
Tag: <span>diafiltration</span>
Microbial fermentation is used to produce such products as therapeutic proteins, antibiotics, hormones, enzymes, amino acids, blood Âsubstitutes and Âalcohol. These products may be expressed by the microbial cells themselves, expressed intracellularly in the cytoplasm or, in the case of bacterial cells, in the periplasmic material. Before any intracellularly-produced molecules can be used and further purified, the cells (i.e., E. coli) must be concentrated and set in an Âappropriate buffer (cell washing) before being lysed. Then after lysis, molecules of Âinterest have to be separated from the Âparent cells and then clarified to remove Âcellular debris and other contaminants. Depending on the process used, additional clarification steps may be necessary…