Advantages of Low-Voltage Electron Microscopy (LVEM) for Clinical Nephropathology

Background: Transmission electron microscopy (TEM) is a crucial tool for the investigation of nephropathologies. This technique plays a critical role in the identification of ultrastructural abnormalities with nanometer-scale resolution. TEM can confidently identify ~90% of cases where light microscopy is limited due to minimal pathological abnormalities. Standard high-voltage TEM systems (HV-TEM) operate at accelerating voltages of ≥80 kV and are routinely used for diagnosing kidney disease through production of detailed images of renal cells. However, HV-TEM is limited by its complexity, high costs, and low image contrast unless specimens are stained with heavy metals. This has led many clinics to discontinue the use of TEM, concentrating it in a few major centers. Low voltage electron microscopy (LVEM) is introduced as an alternative to overcome these challenges. LVEM systems are compact, simple to operate and maintain, afordable and produce higher image contrast, making the post-staining step optional. Methods: In this work, TEM images of unhealthy renal cells were collected using LVEM at accelerating voltages of 15 kV and 25 kV (Delong Instruments LVEM 25) and compared to images collected from HV-TEM. Thin sections (~80 nm) were prepared following standard fixation, sectioning and post-staining protocols (0.5% uranyl acetate). Results: LVEM images provided directly comparable image data with enhanced contrast. As expected, the presence of abnormal ultrastructure was recognized in different unhealthy cells (Figure 1), as such as, (a) fingerprint-like deposits in renal cells typically observed in Lupus glomerulonephritis disease; (b) Irregular glomerular basement membranes in cells contaminated with Alport syndrome, and (c) the presence of zebra bodies in renal cells characteristic of Fabry’s disease. Conclusion: LVEM showed as an alternative to HV-TEM systems for investigation of nephropathology. LVEM allows for a simple, rapid, high-contrast and high-quality imaging of renal cells. In addition, the proposed technique offers a compact and more cost-effective solution, making EM once again widely accessible for clinical nephropathology.