PCDF

Protein Cystallisation Diagnostics Facility

The PCDF (Protein Crystallization Diagnostics Facility) is made of 2 components integrated in the EDR (European Drawer Rack) inside the Columbus laboratory:

• the Electronic Unit (EU) and the
• Process Unit (PU)

The Electronic Unit (EU) was launched to the ISS, installed in the EDR, with the Columbus launch.

Electronics Unit                                                                               Processing Unit

The Space Shuttle STS-119 (15A) (Discovery) carried the Process Unit containing the 4 reactors filled with the protein to be crystallized in microgravity to the Space Station.

To follow the crystallization, the PCDF disposes of 3 observation instruments (diagnostics)

• A camera to follow the crystal growth
• The DLS (Dynamic Light Scattering) to observe the nucleation process
• The MZI (Mach Zenhder Interferometer) that allows the measurement of the refractive index of the protein solution to determine it’s concentration
  

The data transmitted by these various systems will be received in real time on ground by the B.USOC and the scientists in their UHB (User Home Base); they can then react in real time to modify the experiment parameters.

To modify the experiment parameters the B.USOC will send files containing a sequence of commands (CST) to the Station and the PCDF. This allows the utilization of the various diagnostics, the change of the experiment temperature, the stirring of the protein solution or the injection of precipitant, for example.

On Monday July 27, 2009 Japanese astronaut Wakata disconnected the Process Unit and put it in the shuttle Endeavour Middeck. A big challenge was to make the transfer very quickly in order to keep the protein crystals in the correct temperature range.

On July 31, the shuttle landed at Kennedy Space Centre, Florida. Shortly after the landing, the reactors containing the crystals were moved in a Temperature controlled environment. On Thursday 6 August,  reactors containing the crystals eventually arrived at B.USOC for further analysis.

The PCDF stayed more than three months in the ISS. During this period of time the experiment was followed day by day by a team of scientists (Belgian and Spanish). The experiment was all this time remote controlled by the B.USOC.