RCL2, a potential formalin substitute for tissue fixation in routine pathological specimens
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Published on: December 25, 2017
Noraidah Masir1, Mahdiieh Ghoddoosi, Suhada Mansor
1Pathology Department, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia. noraidah@ppukm.ukm.my
Aims:
To investigate RCL2 as a fixative for tissue fixation in routine histopathological examination and to assess tissue suitability for ancillary investigations.
Methods And Results:
Forty-nine samples from 36 fresh specimens were cut into three equal pieces and fixed in RCL2 diluted in 100% ethanol, RCL2 in 95% ethanol, or neutral buffered formalin as control. Suitability for microtomy, quality of histomorphology, histochemistry, immunohistochemistry, fluorescent and silver in-situ hybridization analysis and extracted genomic DNA were assessed. Microtomy was straightforward in most tissue blocks, but there was difficulty in cutting in approximately a quarter of samples, which required careful handling by an experienced technician. There were no significant differences in tissue morphology between RCL2- and formalin-fixed tissues (P=0.08). Generally, the quality of histochemical staining, immunohistochemistry and in-situ hybridization were comparable to that of formalin-fixed tissues. Inconsistent immunoreactivity was noted, however, with antibodies against pan-cytokeratin and progesterone receptor. Genomic DNA concentration was higher in RCL2-fixed tissues. Using RCL2 diluted in 95% ethanol did not affect fixation quality.
Conclusion:
RCL2 is a potential formalin substitute suitable as a fixative for use in routine histopathological examination; however, difficulty in microtomy and occasional discrepancies in immunohistochemical reactivity require further optimization of the methodology.
