Propagation based phase contrast x-ray imaging of Caenorhabditis elegans

Introduction: Imaging of multicellular organisms with nano-scale resolution is one of the challenges of modern life sciences. To solve biological problems, often the combined information of several microscopy techniques is necessary. While confocal fluorescence microscopy and optical super-resolution fluorescence can detect the distribution of markers in live cells, electron microscopy (EM) offers highest resolution in fixed specimen. This, at the price of invasive sample preparation involving fixation, cutting and staining. Yet another important contrast is provided by x-ray microscopy which can yield quantitative density distribution in bacterial cells[1]. At the P10 nanofocus holography endstation at PETRAIII we performed a full-field phase contrast x-ray tomography on the multicellular nematodes Caenorhabdits elegans which serve as model organism for biological research fields including neuroscience, cell biology and signaling[2, 3]. This correlative imaging experiment uses protocols from EM[4] and molecular neurogenetics [5].