Despite an ever-expanding range of additional capabilities for micro-CT systems, the key application for micro-CT remains the production of 3D datasets of a sample’s structure or composition. Whether these datasets are used to quantify material characteristics such as porosity, used as input for numerical models, or are simply being used to gain a better understanding of the interior of a sample, image quality remains paramount to obtaining reliable and reproducible results.

Cryo-electron tomography (cryo-ET) has become an established technique within structural biology for observing and characterizing biological samples in their close-to-native state on a molecular level. Cryo-ET provides an unparalleled level of structural detail. However, it requires a specimen thin enough (typically less than 200nm) to allow an electron beam to pass through it. Current state-of-the-art sample preparation methods use Focused Ion Beam (FIB) milling to achieve this. FIBs using a Gallium ion source are already widely used in the scientific community. These types of instruments offer unprecedented resolution and precise milling but accurate sample preparation is time consuming creating a bottleneck which often limits the overall throughput.

Traditional techniques in cell and tissue microscopy can provide information about details hidden under the surface of cells and tissues. However, this information is typically two-dimensional and lacks context. Current techniques are shifting towards a more holistic approach, that combines X-ray micro-computed tomography (µCT) and electron microscopy to reveal morphological and ultrastructural information ranging from the structure of whole organisms and tissues down to the sub-cellular details.