Correlative x-ray microscopy and transmission electron microscopy for ultrastructural analysis of zebrafish tissue

We established a correlative workflow combining X-ray microscopy (XRM) and transmission electron microscopy (TEM) to investigate the ultrastructure of zebrafish neuromasts. Zebrafish tissues were processed using conventional TEM embedding protocols and first imaged with XRM to obtain three-dimensional information and to localize the neuromast within resin blocks. The XRM previews enabled accurate trimming and rapid identification of target regions, reducing the need for repeated semi-thin sectioning and toluidine blue staining. Subsequent TEM analysis revealed ultrastructural details including cell-to-cell contacts and organelle morphology. Our study demonstrates that integration of XRM with TEM increases efficiency, minimizes tissue loss, and improves orientation accuracy for ultrastructural analysis. This correlative approach provides a valuable workflow for volume electron microscopy, applicable to the observation of the neuromast and various other tissues.