Epoxy Resin Embedding of Animal and Human Tissues for Pathological Diagnosis and Research

Application Note for Leica EM AMW - Life Science Research, Medical Research

August 19, 2016

Ultrastructural analysis
Epoxy resin embedding of different tissues e.g. animal tissues, human tumours and non-neoplastic lesions

Cacodylate buffer (0.1M)
Fixatives: modified Karnovsky fixative (2% paraformaldehyde + 2.5% glutaraldehyde in 0.1M cacodylate buffer); Osmium-tetroxide Os04 (1% in 0.1M cacodylate buffer)
Ethanols (50%, 70%, 95%, abs.)
Acetone abs.

Epoxy resin (all EPON components from Electron Microscopy Sciences, Munich/Germany):
EMbed 812 90g #14960
DDSA 60g #13710
NMA 40g #19000
DMP-30 3g #13600

Fixation protocol
The tissues were fixed in the modified Karnovsky fixative generally by immersion overnight (at minimum 4h at room temperature). Then pieces of approx. 1mm3 were cut with a sharp razor blade and processed for embedding in the Leica EM AMW.

Fig.1: Mouse liver (immersion fixed). Hepatocytes with organelle-rich cytoplasm and round cell nuclei containing prominent nucleoli; in between a blood sinusoid with preserved space of Dissé and bile canaliculi with numerous microvilli. Original magnification: 1,250x.
Fig.2: Mouse liver, cell details. Mitochondrium, nuclear membrane, RER, and glycogen. Original magnification: 20,000x.
Fig.3: Mouse kidney, cortex (immersion fixed). Parts of a proximal and of a distal renal tubule with blood capillaries (filled with erythrocytes) in between. Original magnification: 1,250x.
Fig.4: Mouse kidney, detail of a cell of the distal renal tubule. The cytoplasm displays convolutions of the cell membrane and numerous mitochondria. Original magnification: 10,000x.