1. Culture medium filtration
Culture medium are artificially formulated nutrients for the growth and maintenance of microbial, plant and animal tissues.
They are widely used in pharmaceutical processes such as biological fermentation and cell culture.
Due to the destruction of the active components in some media after autoclaving, it is necessary to remove bacteria and mycoplasma through filtration to ensure sterility.
Different media contain different components. For protein and medium with more saccharides should adopt the form of multi-level progressive filtration to ensure the
filtration quantity and the efficiency of terminal sterilizing filter element.

2. Buffer filtration
A buffer is a solvent that resixes PH changes when a small amount of acid or base is added. In biopharmaceuticals, such as vaccines, blood products,
and monoclonal antibodies, buffers are used to purify the environment in the production process.
It is recommended to filter the buffer with a sterilizing grade filter. If the filter is used, it can effectively protect the use of terminal sterilizing filters.
On the one hand, the buffer is filtered to protect the service life of downstream chromatography column and ultrafiltration membrane.
On the other hand, it is to ensure the quality of the final vaccine.

3. Growth factor filtering
Growth factor is a kind of cytokine with the activity of stimulating cell growth. It is a kind of polypeptide substances that regulate cell growth and other functions
by inducing and binding with specific cell membrane receptors. At present, most growth factors are obtained by bioengineering technology, such as insulin

4.Monoclonal antibody (mAb)
Monoclonal antibody (mAb) is the use of monoclonal technology to prepare antibodies, at present, large pharmaceutical companies have joined the field of monoclonal antibody, During the purification of monoclonal antibodies, a purification process is used to separate the target protein from the impurity.