Downstream processing is the initial step of a biomanufacturing process to harvest cell culture containing highly-expressed active pharmaceutical ingredients (APIs). This is then purified and concentrated for final product formulation and commercialization.
Culturing cells and allowing them to perforate in a laboratory setting to produce advantageous active pharmaceutical ingredients (APIs), is becoming one of the fastest-growing areas in the field of biotechnology. Much of this success is owed to the fast-paced modernization of technologies for cell culture such as: fermentation, harvesting, and purification.
Through modernized technology under Escovaccixcell和Esco Aster, Esco can cater to various biotechnology and biopharmaceutical companies with an automated cell harvesting process, from start-up to large-scale.
Automated harvesting of cells eliminates laborious steps when manually harvesting cells from a system. Different Tide Motion bioreactors are each equipped with its own harvesting system. The harvesting process uses the same conventional method of harvesting adherent cells.
Microfiltration can be used at the start of the downstream process to clarify the feed beyond what was accomplished in the upstream harvest and centrifugation/clarification.
超滤 is used between chromatography steps to concentrate the product and change the buffer conditions to prepare it for subsequent chromatography steps.
消毒等级直接流过滤 involves the use of nanofiltration cartridges to eliminate microbial organisms and insoluble proteins, to remove adventitious and endogenous viruses, and to serve as a sterile filtration process to the product in preparation for final formulation.
与上述膜介质组装在一起的流动设备格式化以影响两种一般流动类型：
直接流过滤 devices allow the process fluid to cross the membrane in essentially a perpendicular flow direction; this provides little or no prevention of particulate build-up or the concentration of other elements that do not fit through the pore structure.
切向流过滤 devices orient the membrane so that process flow sweeps across the active filtration surface, which minimizes pore plugging and surface fouling by concentrated reject elements of the feed. TFF is rapid and efficient method for separating and purifying process flow. It can be used to recover and purify solutions from small volumes (10 mL) up to thousands of liters. With TFF the feed flows tangentially over the surface of the membrane, where a portion flows through the membrane as permeate.
Differential Pelleting: This is the simplest centrifugation type employed wherein particles in a suspension will sediment at different rates based on their different densities. This method is commonly used for cellular harvesting or when producing crude subcellular fractions from tissue homogenate. The downside of this method lies with the heterogeneity of biological particles which can cause contamination and poor recoveries. But this can be further addressed through resuspension and repeating of the centrifugation steps.
密度梯度离心: This method is mainly used for the separation of particles form living cells. But in theory, it can be applied in particle separation of materials with less than 20µm diameter. Density Gradient Centrifugation is a procedure for separating particles in which the sample is placed on a preformed gradient like sucrose or caesium chloride.
High-Speed Centrifuge: This centrifuge is mostly used in more sophisticated applications where higher speeds and temperature control are both critical. High-speed centrifuge can have a maximum speed of 15,000-20,000 rpm.
Eppendorf。（n.d。）。Basics in Centrifugation。取自：https：//handling-solutions.eppendorf.com/sample handling/centrifugation/safe-use-use-of-centrifuges/basics-in-basics-in-centrifugation/
西格玛·奥尔德里奇（Sigma Aldrich）。（n.d。）。离心Techniques。取自：https：//www.sigmaaldrich.com/technical-documents/articles/Articles/biofiles/centrifugation-separation-separations.html#:~: text = the%20simplest%20Form；20faster。
Stephenson, F. (2016).取证和父亲鉴定。科学方。取自：https：//www.sciendirect.com/science/article/pii/b97801280215000138
电泳has gained high importance in the era of genome sequencing with its ability to provide speed and accuracy during nucleic acid analysis. It helps to distinguish DNA fragments of different lengths.
DNA Electrophoresis: Agarose gel is most commonly used in this type of electrophoresis. Its large pore structure allows the easy movement of large molecules; however, having said that, it is not suitable for smaller molecules.
