Introduction
Non-gynecological specimens in our laboratory are triaged for cross-contamination of malignancy between samples during batch staining using non-fixed tissue and water-based Toluidine blue stain. The highly contagious nature of the SARS-CoV-2 virus required modifications of processing procedures to increase safety for laboratory personnel. We evaluated the effectiveness of alcohol-fixed Thionin stain to replace the Toluidine Blue stain to address this issue.
Materials and Methods
Matched slides were prepared using Toluidine blue and Thionin stain from the same cytology sample using the procedures below: As seen in Table 1
Results
Thirteen samples were evaluated and compared for cellularity and presence of potentially abnormal cells. 100% concordance was achieved between the two stain evaluations. Six cases (46%) necessitated separate staining due to high cellularity (n=1) or the detection of abnormal cells (n=5). Seven (54%) were deemed suitable for batch staining.
Conclusions
Slides prepared using > 70% alcohol-based Thionin stain were as effective as the water-based Toluidine blue stain to meet the regulatory standard of cytospecimen triage for cross-contamination with the added benefit of fixing the cells, thus reducing viral exposure risk to laboratory personnel.
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PST119