What your cells see

The Oxygen 2011 conference was the third meeting of COST Action TD0901, part of a Europe-wide cooperation in science and technology, focusing on hypoxia sensing, signaling and adaptation. The interested audience at the training school of this year´s conference got to watch how oxygen measurements can be done with high spatial resolution in cell culture plates. To show the live performance of the PreSens systems Dr Sarina Arain and Dr Gernot T. John used a set-up combining the SDR SensorDish® Reader and an oxygen microsensor in a micromanipulator. Doing live measurements with these devices they wanted to illustrate their presentation on investigating oxygen gradients within multidish wells. The microsensor in a micromanipulator allowed measurements in different depths or from the center towards the walls of a multidish well. With the SDR the oxygen content at the bottom of the well could be determined. 

The measurements showed the inhomogeneous distribution of oxygen within a well of HeLa cell culture. The oxygen level decreased towards the cell layer and dropped rapidly in close proximity to the cells. Near the cell layer the microsensor as well as the SDR measuring from the bottom showed the same oxygen values. The set-up gave an exact, detailed picture of oxygen gradients and distribution within a multidish well. It was also shown that using too low medium volume or cell densities, no oxygen consumption can be detected due to rapid diffusion of atmospheric oxygen into the medium.
"It is always risky to show live measurements in front of such a big audience", said Dr John. But even problems with one of the laptops immediately before measurements could not keep the PreSens team from impressively demonstrating the necessity of oxygen measurements under hypoxic conditions. Participants at the training school got to witness how reliable measurement results could be obtained with these systems - valuable tools for their research.