Gold stain compatibility with synchrotron XRM for ExXRM

Determine whether gold-based metallic stains produced by NanoProbes GoldEnhance LM deposition onto diaminobenzidine (DAB) reaction products in expanded brain tissue are compatible with synchrotron X-ray microscopy without exacerbating heat damage, or whether signal enhancement using a different contrast agent yields better imaging outcomes under synchrotron conditions.

Background

The study achieves contrast in expanded tissue using DAB-based Unclearing followed by gold deposition (GoldEnhance LM) and demonstrates cell body visibility with laboratory X-ray microscopy. However, the author cautions that gold’s strong X-ray absorption may intensify heat damage at synchrotron fluxes, potentially compromising expanded hydrogels even under cryogenic conditions.

Given synchrotron XRM’s high brightness and speed, validating whether gold stains can be safely and effectively used—or identifying superior alternative contrast agents—is essential for scaling ExXRM to large volumes and resolving finer neuronal structures relevant to connectomics.