Hierarchical sample storage system

In one embodiment, a cold storage system for biological samples has one or more freezers, each freezer having one or racks, each rack receiving one or more boxes, each box receiving one or more sample containers. In addition to the biological sample, each sample container has a unique passive RFID tag. Control electronics in each box energize reader coils to query individual RFID tags. Control electronics in each rack communicate with and provide power to the control electronics of each corresponding box, and control electronics in each freezer communicate with and provide power to the control electronics of each corresponding rack, and a host computer communicates with the control electronics in each freezer. In each instance, communication and power provisioning is implemented using magnetic inductive coupling. The system is able to determine the identity of each sample container in the system and maintain that information in a database.