Bringing EDS to life: sample considerations for biological element analysis

Energy dispersive X-ray spectrometry (EDS) provides biologists with colourful element-based compositional information in addition to greyscale ultrastructural data produced with standard electron microscopy (EM), aiding the correct identification of structures and labels. A crucial aspect of all biological EM, including EDS, is the preparation of specimens with the aim of preserving and imaging samples as close to their living state as possible. The best option is freezing samples rapidly and imaging them in their frozen-hydrated state. However, the samples are sensitive to the electron beam requiring low dose imaging methods to avoid damage, and the low contrast makes identification of ultrastructure difficult. Chemical fixation allows the addition of contrasting agents and provides greater stability in samples, but prolonged preparation techniques may result in changes to ultrastructure and potential extraction of elements.

In this webinar, the speakers discuss the challenges of biological EDS and provide information about sample preparation methods and imaging conditions in order to maximise results -- from traditionally prepared samples to unstained specimens to cryo-electron microscopy of vitrified samples (CEMOVIS) -- to identify and image cell ultrastructure in both transmission and scanning electron microscopy.

In this webinar, you will learn how:

• Understand the added value of compositional information for the identification and interpretation of cell ultrastructure.
• Recognise the challenges specimen preparation poses for EDS mapping and analysis in both TEM and SEM.
• Familiarise themselves with the range of techniques that are available with EDS, the type of information that can be obtained about biological samples in general and how EDS can be used to address a range of research questions.