Marking transgenic Xenopus froglets with passive micro transponders.

Standard methods to mark Xenopus laevis individuals like tattooing or clipping toenails are inappropriate for the fast growing and regenerating small froglets and the previously used transponders are too large. In this study we successfully adapted micro transponders to tag these animals. Using these new transponders one can now tag small froglets directly after metamorphosis, which has not been possible previously. This new technique makes the breeding of transgenic frogs most efficient, because the frogs do not have to be kept separately and they grow much faster when kept together in large containers.