Supplementary Figure 3: Technical drawing of the very compact Roadrunner inline sample-viewing microscope.

Main component is an Olympus LMPLFLN50X light microscope objective with 50x magnification and a numerical aperture of NA=0.5 with a 0.5 mm diameter hole through its center for the X-rays to pass through. The X-ray beam path is indicated in red. To reduce scattering background a 0.5 mm outer diameter and 0.35 mm inner diameter molybdenum tube is inserted into the drill hole extending to about 3 mm before the sample position. The optical light path is indicated in green. After leaving the microscope the light path is deflected by 90 degrees using a prism mirror, which is also equipped with a drill hole to pass the X-rays. After exiting the tube lens (f=80 mm), the magnified image of the sample is recorded using a ProSilica GC1360 Gigabit Ethernet CCD camera. The spatial resolution of the microscope setup is better than 1 μm.