Micro-computed tomography for visualizing limb skeletal regeneration in young Xenopus frogs.

For studies of vertebrate limb regeneration it is often desirable to visualize the regenerated skeleton, which is mostly cartilage, and also section the specimen for histological or immunohistochemical visualization of other tissues. However, the normal skeletal staining techniques are incompatible with immunohistochemistry. Here, we describe a contrast-based micro-computed tomography (microCT) method for direct and nondestructive observation of regenerated cartilage spikes in Xenopus frog limbs. In addition, we show that contrast based microCT imaging is compatible with immunohistochemistry protocols. This approach provides versatile and high contrast images of the cartilage allowing us to measure the regenerated skeletal structure in detail as well as carrying out the other types of analysis. It opens a wide range of potential microCT applications in research on vertebrate limb regeneration.