DIY Polarization: Validated Low-Cost Alternative for Birefringence in Histological and Cytological Analysis.

Abstract

Introduction: Birefringence analysis is an essential tool in both histological and cytological diagnostics, particularly with stains such as picrosirius red for collagen and Congo red for amyloid. However, polarized light microscopy remains limited in many laboratories due to cost and accessibility barriers. We describe a low-cost "do-it-yourself" (DIY) approach using commercial polarizing films to adapt a standard brightfield microscope for birefringence visualization.

Methods: Thirty gastrocnemius muscle sections stained with picrosirius red were analyzed using both a commercial polarized light system and the DIY setup. Quantitative image analysis was performed with ImageJ, and agreement between methods was assessed with ROC curve analysis.

Results: The DIY method achieved an AUC of 0.6252 (p = 0.0309) and 99% inter-observer concordance, demonstrating fair agreement with the commercial system.

Conclusion: This simple, validated method expands access to birefringence-based diagnostics and has potential applications in cytological contexts, such as amyloid detection in fine-needle aspirates and collagen assessment in cytospin preparations.