AVT Oscar F810-C sensor used by Robot vision system to pick stem cells
Coupling a robot with machine vision and laboratory automation software has resulted in a system that automates the picking of stem cells.
Under certain conditions, stem cells can be induced to become other types of cell such as blood or muscle cells though a process known as differentiation. Because of this, scientists and researchers can use them to regenerate diseased or damaged tissue.
To grow colonies of stem cells, single stem cells are extracted from tissue and transferred onto a Petri dish that contains a nutrient. This allows the cells to undergo numerous cycles of cell division and appear as tightly knit colonies, less than 1 mm across, that adhere to the bottom of the Petri dish. Each colony consists of identical stem cells.
As long as the stem cell colonies are grown under appropriate conditions, they remain undifferentiated. If two colonies grow together, such that they touch, it is not possible to pick a pure line of stem cells. These groups (resembling a figure of eight) and colonies that that have started to differentiate (that can be seen by changes in their shape) must not be selected for picking.
Only undifferentiated pure colonies of stem cells must be picked from the Petri dishes and transferred individually into a microtiter plate - a flat plate with 96 wells that act as small test tubes. Here, the stem cells can be further grown or processed to differentiate into specific cell types desired by the researchers.
In the past, the process of identifying undifferentiated stems cells on Petri dishes was carried out manually by trained operators who identified the cells under a microscope. However, there was a lack of consistency between the individuals who picked the cells from the plates and the chance that and the potential that operators might damage the colonies, pick the wrong ones, or pick multiple colonies.
Robot vision
To automate this process, engineers at paa (Peak Analysis & Automation, Farnborough, UK; www.paa-automation.com) in conjunction with the Wellcome Trust Sanger Institute (Hinxton, UK; www.sanger.ac.uk) have developed a vision-based robotic system called automate.it pixcell for the detection, isolation and picking of stem cell colonies from Petri dishes. After picking, the robotic system transfers the cells to wells in microtiter plates where they can be treated to create specific cell types.
To achieve their goals, extensive use was made of off-the shelf hardware and software. An RP-Series robot and robot controller from Mitsubishi Electric (Hatfield, UK; http://automation.mitsubishielectric.co.uk) was chosen to move a camera and four picking heads over the Petri dishes, while an image capture and analysis software package from Bio Image Systems (Jackson, MI, USA; www.bioimage.net) enables images of the Petri dish to be captured and undifferentiated pure colonies to be detected and mapped. The picking head itself, which ensures that the stem cells colonies are delicately picked from the dish without physical damage, was developed at, and licensed from, the Wellcome Trust Sanger Institute.
Scheduling and control of the hardware and software was performed using Peak Analysis & Automation own custom Overlord3 software. This enabled the vision-based robotic system to control the flow of the entire automated process and to schedule the timing of events through the use of a drag and drop interface.
More specifically, the Overlord3 software acquires and processes image data from the camera and schedules the movement of the robot and the timing of cell picking and deposition. The software also controls the scheduling and timing of associated pneumatic, pumping and calibration operations performed through an I/O interface from the Mitsubishi robot controller hardware
http://www.vision-systems.com/articles/print/volume-19/issue-2/features/robot-vision-system-picks-stem-cells.html