The new liquid-nitrogen cooling system at the Centre for Advanced Laser Applications (CALA) fulfills all prerequisites for secure long-term storage of blood donated to the Lasers4Life project. In the Biobank, the samples are maintained under cryogenic conditions, i.e. at less than -150°C in the gaseous phase over liquid nitrogen. The 11-tier system can accommodate approximately 60,000 (0.5-ml) samples of plasma or serum. Storage and retrival of samples is carried out by an integrated robotic system. The latter steps are performed at a temperature of -100°C, so that the whole operation takes place without interruption of the refrigeration chain.
In terms of both storage and handling, the new system has marked advantages over the previous procedure, in which samples were manually stored at -80°C. Most importantly, thanks to the use of ultracold liquid nitrogen, samples remain at the set temperature even in the unlikely event of a power cut lasting for several days. They can also be stored for at least 10 years without any alteration or loss. This means that samples can always be (re-)analysed with the latest generation of lasers available, in order to extract still more information than could previously be obtained.