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The purification of proteins from complex cell culture samples is an essential step in proteomic research. Traditional chromatographic methods often require several steps resulting in time consuming and costly procedures. In contrast, protein purification via membrane adsorbers offers the advantage of fast and gentle but still effective isolation. In this work, we present a new method for purification of proteins from crude cell extracts via membrane adsorber based devices. This isolation procedure utilises the membranes favourable pore structure allowing high flow rates without causing high back pressure. Therefore, shear stress to fragile structures is avoided. In addition, mass transfer takes place through convection rather than diffusion, thus allowing very rapid separation processes. Based on this membrane adsorber technology the separation of two model proteins, human serum albumin (HSA) and immungluboline G (IgG) is shown. The isolation of human growth hormone (hGH) from chinese hamster ovary (CHO) cell culture supernatant was performed using a cation exchange membrane. The isolation of the enzyme penicillin acylase from the crude Escherichia coli supernatant was achieved using an anion exchange spin column within one step at a considerable purity. In summary, the membrane adsorber devices have proven to be suitable tools for the purification of proteins from different complex cell culture samples.

Spodoptera frugiperda-9 (Sf-9) cells used in conjunction with the baculovirus expression vector system (BEVS) represent a promising platform for the rapid development and manufacture of protein complexes and virus-like particle (VLP) products. Several studies have described the superiority of single-use wave-mixed bioreactors although reusable stirred and, more recently, single-use stirred bioreactors have also been successfully applied. Due to their bioengineering characteristics (more homogeneous energy dissipation, reduced foam formation), wave-mixed systems are often preferred. However, a direct comparison of the influence of single-use wave-mixed and single-use stirred bioreactors on cell growth and protein expression in Sf-9/BEVS-based production processes was still lacking. We investigated Sf-9 cell growth and expression of a recombinant secreted alkaline phosphatase (rSEAP) in the wave-mixed BIOSTAT® RM as well as the stirred UniVessel® SU and a serum-free culture medium. Irrespective of the bioreactor system, comparable growth, substrate, and metabolite courses as well as peak cell densities (>1.2 × 107 cells mL−1) were observed in Sf-9 cell expansions performed in batch mode. Additionally, identical rSEAP quality and maximum rSEAP activities were found in biphasic productions in both bioreactor systems. Concluding, comparability of single-use wave-mixed and stirred bioreactors for insect cell culture processes was demonstrated for the first time.

For the production of recombinant proteins for clinical use animal cell cultivation is used. Only these cells are able to perform correct folding and glycosylation of the desired protein. As the production process is expensive and long, cheaper and/or swifter cultivation routines are required. Chinese hamster ovary (CHO) cells were used to examine the expansion of cells and the production of recombinant human growth hormone in different cell culture systems which are supposed to achieve higher cell densities and product concentrations compared to conventional cell culture systems. The CHO cells were grown in suspension in serum-free, low-protein medium. Five different culture systems were used for batch-cultivation: Biostat B, BelloCell 500, spinner flask, RCCS-D and miniPERM. The systems differed in oxygen supply and medium agitation. While cells are agitated by stirrers in Biostat B and spinner flask, the whole medium is revolved in BelloCell 500, RCCS-D and miniPERM. Unlike the other systems the BelloCell 500 retains the CHO cells on a matrix. The aim was to maximize cell growth and productivity, which was achieved best in BelloCell and RCCS-D. In a second step the influence of temperature on growth and product formation was examined.