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Updated: Aug 14, 2026
Assessment of Kidney Function in Mouse Models of Glomerular Disease
Published on: June 30, 2018
Immunoelectron microscopy on epoxy sections without deplasticizing to detect glomerular immunoglobulin and complement
S H Brorson1, E H Strøm, F Skjørten
1Department of Pathology, Ullevål Hospital, Oslo, Norway.
Insights
This study introduces a novel immunoelectron microscopy (IEM) technique for renal biopsies, enabling sensitive detection of immunoglobulins and complement C3 in epoxy-embedded tissues without deplasticizing. The method preserves ultrastructure and is ideal for limited biopsy samples.
Area of Science:
- Nephrology
- Immunopathology
- Electron Microscopy
Background:
- Immunoelectron microscopy (IEM) is crucial for diagnosing kidney diseases.
- Traditional IEM requires deplasticizing epoxy-embedded samples, which can damage ultrastructure.
- Detecting antigens like immunoglobulins and complement C3 in renal biopsies is vital.
Purpose of the Study:
- To develop and validate a novel IEM method for renal biopsies.
- To enable immunolabeling of immunoglobulins and complement C3 on epoxy sections without etching.
- To assess ultrastructural preservation and antigen detectability compared to traditional methods.
Main Methods:
- Studied 20 renal biopsies using immunoelectron microscopy (IEM) on epoxy-embedded sections.
- Utilized increased DMP-30 accelerator concentration for immunogold labeling of immunoglobulins and C3.
- Sections were stained with tannic acid, uranyl acetate, and lead citrate; compared with immunofluorescence (IF) on frozen sections.
Main Results:
- Successfully performed immunolabeling of immunoglobulins and C3 on epoxy sections without etching or deplasticizing.
- Demonstrated higher sensitivity of IEM compared to IF in detecting smaller antigen amounts in some IgA-nephritis cases.
- Achieved ultrastructural preservation comparable to standard epoxy embedding.
Conclusions:
- The novel IEM method provides excellent immunolabeling with near-optimal ultrastructure.
- This technique is particularly valuable for limited biopsy material, enhancing diagnostic capabilities.
- This represents the first successful immunolabeling of immunoglobulins on non-etched epoxy sections.
Abstract:
Twenty renal biopsies were studied by immunoelectron microscopy (IEM) after embedding in epoxy resin. Immunogold labeling for immunoglobulins and complement C3 was performed on the epoxy sections, which were not subjected to any kind of etching or deplasticizing prior to the immunolabeling. The concentration of accelerator, DMP-30 (Tri (Dimethyl Amino Methyl) Phenol), was increased in the infiltration and embedding steps far beyond the values normally used to make immunolabeling of these antigens possible on epoxy sections. The sections were stained with tannic acid accompanied by uranyl acetate and lead citrate. Immunofluorescence (IF) for light microscopy was carried out on frozen sections of parallel tissue samples. Some cases with IgA-nephritis demonstrated a higher sensitivity for IEM than IF, in the sense that smaller amounts of antigen were detectable with IEM. Ultrastructural preservation with this method was approximately the same as that usually seen on epoxy-embedded material. By combining excellent immunolabeling with nearly optimal ultrastructural morphology in one procedure, this method is useful particularly in situations where the material available is limited, such as in studies of renal biopsies. As far as we know, this is the first time that immunoglobulins have been satisfactorily immunolabeled on epoxy sections without etching or deplasticizing.
