The present disclosure relates to a radio-frequency identification system for a container, such as a cryogenic container, comprising: a large number of radio-frequency identification tags for cryogenic straws, preferably at least 100 radio-frequency identification tags, each radio-frequency identification tag attachable to or embeddable in a cryogenic straw; an interrogation unit adapted to be placed or integrated inside the cryogenic container; wherein the interrogation unit and radio-frequency identification tags are configured to operate with a frequency of at least 30 MHz. The disclosure further relates to a method of identifying a large number of radio-frequency identification tags in a cryogenic container, preferably at least 100 radio-frequency identification tags, the method comprising the steps of: configuring a radio-frequency identification interrogation unit to transmit radio-frequency interrogation signals in the container with a frequency of at least 30 MHz; configuring the radio-frequency identification interrogation unit to operate in a plurality of different signal propagation modes such that the cryogenic container is divided into a plurality of propagation zones, wherein each propagation zone is associated with a corresponding propagation mode, and wherein only the radio-frequency identification tags within a specific propagation zone are excited when the interrogation unit is in the corresponding propagation mode; and configuring the radio-frequency identification interrogation unit to receive radio-frequency response signals from the radio-frequency identification tags.