Leica AFS2 Automated Freeze Substitution System

The Leica EM AFS2 is an advanced freeze substitution and low-temperature embedding system designed to preserve cellular and tissue ultrastructure with exceptional fidelity for transmission and scanning electron microscopy. The system plays an important role in the Bioimaging Centre's sample preparation workflow, enabling the processing of specimens prepared by high-pressure freezing and supporting applications that require superior structural preservation compared with conventional chemical fixation methods.

Through precise control of temperature profiles, the AFS2 enables automated freeze substitution, resin infiltration and polymerisation at low temperatures, minimising artefacts and preserving delicate cellular structures.

The platform can be equipped with Leica's automated resin handling robot, enabling unattended processing and infiltration of specimens using resins such as Lowicryl HM20 and LR White. These resins are widely employed for immunogold labelling applications, where preservation of antigenicity is essential, allowing the localisation of proteins and other biomarkers at the ultrastructural level. The combination of automated processing and reproducible temperature control provides highly consistent sample preparation while reducing manual handling and operator variability.

By integrating seamlessly with the facility's high-pressure freezing and electron microscopy infrastructure, the Leica AFS2 supports a complete workflow from cryo-fixation through to imaging and quantitative ultrastructural analysis, ensuring researchers can obtain the highest quality electron microscopy data from challenging biological specimens.