Medical engineering is becoming a new science discipline and its growth in our century is astonishing. German researchers have achieved great success in the field of cell cultures from a machine project.
Cell cultures form the basis of day-to-day research work in applications that range from the development of drugs and vaccines to the decoding of functions of individual genes. Until now, cell cultures have been sown, tended, observed and transferred to vessels – all by hand. A new device completely automates these work steps.

Many Unresolved Puzzles
The human genome has been decoded. Of all the puzzles it contains, though, many remain unresolved. We know that the genome provides the blueprint for various proteins, the building blocks of every cell. But what role do they play? Which proteins control cell division in a healthy body, for instance? And what takes place in tumour tissue in which cells incessantly subdivide and control over proteins gets out of hand?

To get to the bottom of the functioning of various proteins, researchers start by cultivating cell cultures. They add a few cells to a Petri dish, add nutrients and regularly check for cell growth. Once suitable colonies of cells have taken hold, the researcher uses a pipette to transfer these to a new vessel where investigation of the cells can continue. To date, for the most part, researchers have had to carry out these steps by hand – in time-consuming routine work.

Researchers at the Fraunhofer Institute for Manufacturing, Engineering and Automa- tion, in Stuttgart, at the Institute for Physical Measurement Techniques, in Freiburg, and at the Institute for Applied Information Techno- logy, in Sankt Augustin, have now teamed up with colleagues at the Max Planck Institute of Molecular Cell Biology and Genetics, in Dresden, to create a system that completely automates the process of cultivating cells.

The device consists of an array of modules. One is a robot that transports the vessels containing the cell cultures, known as multititer plates, from one place to the next. Dr Albrecht Brandenburg, group manager at the Institute for Physical Measurement, describes another module: “A microscope regularly inspects the cells to assess the status and growth of the cultures. It transfers the plates to the microscope stage, focuses, switches lenses and activates the light sources it needs. The entire optical system is designed to withstand and operate in the high-humidity conditions the cells require. The results of microscopic analysis are fed into the system control, a capability never seen in auto- mated cell cultivation before.”

As an example, a computer program assesses the microscope images and checks to determine how densely the surface of the vessel is already covered in cells. If suitable cell colonies have formed, another module, a hollow needle, picks cells ranging between 100 ym and 200 ym in size and transfers them to a new container. System users can train the software responsible for this pattern recognition – and, thus, for identifying the cells themselves as such. In the case of new cell types, they can define sample areas as foregrounds and backgrounds. In subsequent work steps, the system identifies the cell type automatically.

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