Aims In intraoperative frozen tissue section laboratories (FS laboratories) conventional practice for mounting coverslips on tissue slides involves the use of xylene-based mounting agents, such as Pertex. However, toxic vapours pose a risk to biomedical laboratory scientists (BLS) and pathologists who handle the wet slides to provide fast and urgent diagnostic results to surgeons during operations. Our study aims to evaluate non-toxic mounting agents to substitute Pertex, preferably with a fast curing time suitable for the demands of the new digital era in pathology.

Methods Five non-toxic mounting agents were purchased and tested through six different protocols and compared to xylene-based Pertex as our gold standard. With light microscopy, tissue slides were quality assessed by BLS. Mounting agents, which were evaluated comparable to Pertex, were also evaluated by a pathologist, hence scanned digitally and re-evaluated.

Results The protocols for Eukitt UV, Eukitt UV R-1 and Eukitt UV R-2 had significantly more artefacts (bubbles) compared to gold standard Pertex (p<0.0001, p=0.004 and p<0.0001, respectively) and assessed inadequate as replacements. Neo-Mount and Tissue Mount were assessed applicable regarding quality, but curing times were long. Tek Select UV showed promising results in both quality and fast curing time (protocol was <2 min).

Conclusions Toxic mounting agents need replacement to health guard professionals, and also digital pathology is revolutionising laboratories. A digitalized FS laboratory requires fast dry/cured slides for digital scanning. Therefore, a substitute for the FS laboratory should have the qualities of being non-toxic to handle and having a fast curing time, and a UV-based mounting agent may solve both requirements.