Optimizing Re-staining Techniques for the Restoration of Faded Hematoxylin and Eosin–stained Histopathology Slides: A Comparative Study

Abstract

Hematoxylin and eosin (H&E)-stained slides inevitably deteriorate over time, frequently becoming unreadable. Reutilizing these slides can reduce the need for additional serial sections, particularly when the target region is no longer available in the tissue block. This study aims to develop efficient protocols for recycling faded H&E-stained slides, providing benefits for future research on stored samples. Seventy-one faded slides, representing a variety of tissue types and pathologies, were randomly divided into two groups. Slides were de-stained and re-stained using the conventional procedure and a modified Tris and HCl procedure. Three observers independently assessed all slides based on predefined parameters. The stability of the re-stained slides was re-assessed in 6 months. The modified Tris and HCl method yielded significantly higher scores compared to the conventional method for crispness of staining, nuclear staining, cytoplasmic staining, and vibrancy of staining (p < 0.05), as well as greater durability, as evidenced by minimal score reduction 6 months after staining. Thus, incorporating a Tris and HCl step into the process effectively enhances and restores faded H&E slides, offering a valuable technique for revitalizing histology slides for future research and educational purposes.