Mounting agents with low toxicity and with fast curing time for digital pathology in the intraoperative frozen section laboratory

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.