Upstream / Downstream

For upstream processing specifically engineered cell lines are developed and cell banking / cell storage is established. The cells, usually mammalian cells or microorganisms like bacteria, are cultivated in appropriate culture media. During the process of cell expansion, starting from small vials, the culture size is increased gradually until the cells can be transferred into large bioreactors. This enables the production of specific biomolecules on a large scale. The cell cultures are often supplemented with insulin, transferrin or cell-specific growth factors to optimize cell growth and yield.

These biomolecules, e.g. proteins, have to be separated from the culture medium or extracted from the inside of the cells. For these extraction procedures special cell lysis buffers are used. The molecules are further purified by several steps of centrifugation, filtration and different chromatography methods to remove other proteins or nucleic acids like RNA and DNA. During these steps suitable buffer solutions are used to maintain defined purification conditions like pH and conductivity to stabilize the target protein while protecting them from unwanted contaminations. This ensures structural and functional integrity of the biomolecules during downstream processing.