Multiple immunofluorescence labelling of formalin-fixed paraffin-embedded (FFPE) tissue

Area of Science:

• Biomedical research
• Molecular pathology
• Cell biology

Background:

• Traditional methods for gene expression analysis in tissue samples include immunohistochemistry on FFPE sections and immunofluorescence on cryosections.
• Both methods have limitations, creating a need for routine, high-quality immunofluorescence labeling of FFPE tissues.

Purpose of the Study:

• To develop and validate a robust method for high-resolution immunofluorescence labeling of FFPE tissues.
• To enable researchers to utilize archival FFPE specimens for advanced immunofluorescence investigations.

Main Methods:

• Optimized protocol combining antigen retrieval, indirect immunofluorescence, and confocal laser scanning microscopy.
• Demonstrated utility on human kidney, human breast tissues, and invasive breast cancer tissue microarrays.
• Established short-term (4°C) and long-term (-20°C) storage conditions for stained slides.

Main Results:

• Successful high-resolution immunofluorescence labeling of FFPE tissues was achieved.
• The method allows for higher resolution imaging of antigen localization compared to immunohistochemistry.
• Multiple antigens can be labeled simultaneously on a single FFPE section.

Conclusions:

• The developed method bridges cell biology and pathology, enabling the use of vast FFPE archives.
• Cell biologists can now leverage archival material and tissue microarrays for in vivo sample analysis.
• Pathologists can characterize cell populations, test multiple biomarkers, and define cellular heterogeneity with greater accuracy.