Linkam, a market leader in temperature and environmental-controlled microscopy, presented its range of cryo workflow solutions and sample characterisation tools at Microscopy and Microanalysis (M&M) 2022.
Linkam previewed its new cryo plunger – CryoGenium – an exciting development in electron microscopy (EM) grid vitrification.
Imaging of biological samples embedded in vitrified ice has become of great interest in recent years as it provides several advantages: i) the biological sample is in a fully hydrated state with superior preservation down to ultrastructural level; ii) a vitrified sample is naturally compatible with the vacuum required for EM/single particle (SPT)/correlative light and electron microscopy (CLEM); and iii) cryo-fluorescence provides very low photo-bleaching and high signal-to-noise imaging.
Preparation and handling of vitrified samples normally requires special skills and techniques. The novel design of the Linkam CryoGenium makes this a simple and reproducible process.
CryoGenium addresses several common issues that are found in a conventional plunge-freezing set-up. Typically, the sample is prepared on an EM grid and excess liquid is removed inside a humidity chamber using blotting paper to control the ice thickness of the frozen sample.
The design replaces the common blotting mechanism to improve process stability and repeatability. The system introduces real-time optical observation of the sample with control of the liquid film thickness by adjusting the speed at which the sample is drawn from the fluid as well as thinning of the film thickness by controlled suction. The correct conditions for plunging can be confirmed by the real-time optical observation, and plunging is followed by automated loading into either a special cryo-holder or a cryo-transfer container.
CryoGenium provides a platform that increases the success rate and quality of plunged grids, enabling improved efficiency and less time wasted at transmission EM (TEM), resulting in cost savings.
The Linkam CMS196V3 Cryo-Correlative Stage provides another cryo correlative tool enabling the full workflow of CLEM to maximise efficiencies in the laboratory. Cryo-CLEM is a rapidly emerging technique that combines the advantages of fluorescence light microscopy FLM) with three dimensional (3D) cryo-electron tomography (cryo-ET) to reveal the ultrastructure of target molecules with specific cellular functions. As well as maintaining the integrity of the sample vitrified by liquid nitrogen cooling, the Linkam CMS196V3 stage enables contamination-free sample handling and transfer for optical microscopy imaging.