HYDROMEL Project - Demonstrator 3
Development of a fully automated cellular microinjection system
Presentation – The aim of the demonstrator 3 is to present a fully automated cellular microinjection system. This system is designed to inject Xenopus Laevi oocytes, a well known model in biology as it can be easily injected with nucleic acids (e.g DNA or DNA) to study the corresponding proteins. Recent works have shown that X. Laevi oocyte is a suitable and reliable model to study the structure and functions membrane channels and transporters. Transporters are membrane proteins that are present in all organisms and control the influx and the efflux of nutrients, ions, environmental toxin or drugs. Transporter-mediated drug absorption and excretion is a key process in the pharmacological response and it has been shown that several endogenous or exogenous compounds can modulate their function thus modifying the overall drug efficacy and safety. Oocytes injected with nucleic acids coding for drug transporter express functional proteins that display identical characteristics to that observed in vivo.
The actual microinjection technique relies on a manual approach that considerably limits the number of cells that can be microinjected. In this automated system only the prefilled microinjection needles have to be manually mounted onto the system. After placing the cell suspension the system sorts out individual oocytes (Cell Sorting & Selection module), they are transported to the immobilization site where they get injected and finally released into a container (Cell Injection module). The aimed throughput is about 15 oocytes per minute.
Cell Sorting & Selection module – The task of this module is to automatically select individual oocytes out of a suspension. The suspension is loaded into the module and constantly moved to avoid cell adhesion. A vision algorithm is used to control the oocytes’ quality and a fluidic system removes the oocytes out of the suspension and transports it to the subsequent injection module.
Cell Injection module – The task of this module is to automatically inject individual oocytes and to collect them in a container. After the oocyte is transported to the cell injection module, depending on the stage of oocyte itself orients it and falls with the animal pole facing upwards into the immobilization site. The oocyte is then transported to the injection site where a compound is injected and finally the oocyte is moved to the release site for collection. To increase the throughput, this module is built in a carousel system, such that simultaneous an oocyte can be immobilized, injected and collected.