A micro optical system design for the observation of cells in the fermentation bioreactor

Bioreactor for cell culture fermentation is the main production equipment for precious pharmaceuticals and biological products, such as vaccines, monoclonal antibodies, enzymes, diagnostic reagents. In order to determine the status of cells, the traditional observation way which is adopted by pharmaceutical enterprise is removing partial media through the mouth of the liquid from the fermentation tank. But the growth status of cells cannot be discovered in real time by this way. In this paper, a method of non-contact observation by use of optical systems for the fermentation bioreactor of cells culture has been proposed. Illumination of the light window is opened above bioreactor liquid level of fermentation. And another observing the window is located below the fermentation liquid, it can tilt to observe the cells in the culture by use of long working distance micro optical system. By changing the focus position of the optical system, the purpose which observes the cells in the culture medium inside of the fermenting tank is achieved. The mobile mechanical structures of micro optical system and lighting system adopt fission design. A long working distance video microscope has been designed for observation, working distance is adopted by 80mm, the total length of the system is 417.69mm, the numerical aperture NA is 0.35, the object square line field is 0.65, and the optical resolution is 1micron and it can view the cells in the culture. Utilizing Gigabit net industrial CCD camera to acquisition image, the cells in bioreactor of fermentation have been automatic real-time monitored through processing and analysis of images in the computer. After the real-time observation, the growth of the cells in the whole fermentation tank can be probably understood. It can be accurately mastered the operation time of the process of cells´ subculture, inoculation and receiving.