The fast imaging of large, intact clinical tissue samples using an improved microscope is reported in a paper published online this week in Nature Biomedical Engineering. This new method enables clinical pathologists to visualize the entire specimen in three dimensions within minutes, resulting in improved diagnostic accuracy, for example of tumour tissue following surgery.

Traditionally, after a tissue sample is surgically removed, a pathologist prepares it for examination by first preserving its structure (through chemical fixation) and then slicing the tissue into thin sections, which are placed on slides for subsequent staining with dyes. As this process is laborious, only a few tissue sections for any given sample are actually analysed with a microscope to inform the diagnosis. This limitation can significantly affect the ability of the clinician to correctly make a decision, possibly leading to misclassifications.

By optimizing a fluorescence microscope that scans thin sections across whole samples, Jonathan Liu and colleagues demonstrate that surgical samples can be imaged within minutes without the need for sample processing. The authors show how the microscope can rapidly identify tumour resection margins, provide more accurate evaluations of clinical tissue samples, by avoiding artefacts generated in standard histopathology protocols, and improve patient diagnosis.