Development of a direct reading system for an RFID-tagged Uni-puck in liquid nitrogen

The Structural Biology Research Centre in KEK has operated macromolecular crystallography beamlines at the Photon Factory. We have developed the sample exchange system PAM and implemented it on the beamlines for high-throughput, remote, and automated experiments. To prevent sample mix-ups by human error, we identify the Uni-pucks using a commercially available cryo-pin with a two-dimensional (2D) code. However, reading the 2D code sometimes fails because of frost growth when the cold cryo-pin is transferred from liquid nitrogen into the air. To achieve reliable identification, we are developing a sample identification system that uses radio-frequency identification (RFID) tags. We successfully read an RFID tag on a Uni-puck placed in a puck-adapter directly immersed in liquid nitrogen.