A method for preserving ultrastructural properties of mitotic cells for subsequent immunogold labeling using low-temperature embedding in LR White resin.

The best available approach of biological sample preparation for transmission electron microscopy currently includes cryoimmobilization by high-pressure freezing (HPF) followed by freeze-substitution (FS). This method has been well established for interphase cells; however, a reliable and easy procedure is still missing for mitotic cells especially because of their fragility and sensitivity to treatments. Here, we present a fast and effective method for HPF/automated FS and LR White embedding of mitotic cells which allows for their controlled and reproducible quality processing. It should be useful in various ultrastructural studies on mitotic cells especially in combination with immunocytochemistry.