Dual-Excitation PARS Virtual Staining

Traditional histochemical staining faces several challenges, including its destructive nature, consumption of limited biopsy tissue, complex multi-step protocols, and generation of chemical waste. Virtual staining with label-free microscopy, particularly dual-excitation PARS, offers a solution by enabling non-destructive, multi-stain visualization from a single tissue section. This approach overcomes the need for additional tissue cuts, reduces preparation time, and preserves samples for downstream molecular and histological analyses. While the current PARS system's scanning speed is a limitation compared to conventional brightfield scanners (e.g., ~33 hours for 1 cm² at 40x equivalent resolution versus <5 minutes), this is attributed to the point-scanned, stage-based raster acquisition and current laser repetition rates, rather than a fundamental PARS limitation. Future improvements in imaging speed are expected through higher-repetition-rate UV excitation and faster beam-scanning architectures, with projected speeds of 35 min/cm² at 40x and 15 min/cm² at 20x. Another challenge is ensuring data generalization across diverse institutions and patients, as this study's models were trained within a consistent imaging and staining setting. Future work will focus on larger, multi-center validation studies and expanded pathologist assessments for task-specific diagnostic endpoints.

The dual-excitation PARS virtual staining system offers substantial enterprise value for pathology laboratories and research institutions. By providing a non-destructive method for obtaining multiple histochemical stains from a single tissue section, it addresses critical issues of limited biopsy tissue availability and the destructive nature of traditional staining. This translates to significant cost savings by reducing the need for chemical reagents and specialized labor, as well as accelerating turnaround times for diagnoses, thereby improving operational efficiency. The ability to generate high-fidelity virtual H&E, Masson's trichrome, PAS, and JMS stains on human and murine tissues, with diagnostic quality comparable to chemical counterparts, enhances the depth of pathological analysis. Furthermore, preserving the original tissue allows for subsequent advanced molecular or immunohistochemical assays on the exact same region of interest, maximizing the utility of valuable samples. This technology positions pathology services at the forefront of digital transformation, offering a scalable solution for comprehensive, rapid, and resource-efficient histological assessment.