Formaldehyde Substitute Fixatives

Moelans, Cathy B.; Hoeve, Natalie ter; Ginkel, Jan Willem Van; Kate, Fiebo J. ten; Diest, Paul J. van

doi:10.1309/ajcphh1b0cocbgom

Cited by 51 publications

(32 citation statements)

References 24 publications

(25 reference statements)

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“…Color and consistence are evident at a glance, while other features such as shrinkage and surface modifications are more subtle. In disagreement with a recent paper [39] that reported some difficulties in handling and sectioning of samples fixed in RCL2, we did not encounter any problems in these preparative aspects. The embedding process that follows fixation may largely modify the physical qualities of samples to be included in paraffin, and influence the ease in sectioning.…”

Section: Resultscontrasting

confidence: 99%

Evaluation of two commercial and three home-made fixatives for the substitution of formalin: a formaldehyde–free laboratory is possible

et al. 2012

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BackgroundFormaldehyde (HCHO) is a gas (available as a 37% concentrated solution, stabilized with methanol). The 10% dilution (approximately 4% formaldehyde) has been used as a fixative since the end of the 19th century. Alternative fixatives are also commercially available or may be prepared in-house in laboratories. Statements by the IARC, along with other USA agencies (CalEPA, RoC/NTP) on the carcinogenicity of formaldehyde for humans renders its substitution in Pathology Departments necessary since the annual use of formalin may exceed 3,500 liters for a medium-large laboratory.To achieve a “formalin-free laboratory” we tested straightforward-to-make fixatives along with registered reagents offered as formalin substitutes.MethodsMore than two hundreds specimens were fixed in parallel with in-laboratory made fixatives PAGA (Polyethylenglycol, ethyl Alcohol, Glycerol, Acetic acid), two zinc-based fixatives (ZBF, Z7), and commercially-available alternatives (RCL2 and CellBlock). Tissue micro arrays were used for morphological and immunohistochemical comparison. Extraction of RNA was carried out to evaluate preservation of nucleic acids.ResultsDifferences compared to formalin fixation were evident in alcohol-based fixatives, mainly restricted to higher stain affinity and considerable tissue shrinkage. Conversely, nuclear detail was superior with these alcohol-based formulas compared to formalin or glyoxale-based recipes. RNA extraction was superior for Z7, PAGA and RCL2 with regard to concentration but relatively comparable regarding quality.ConclusionsAbolition of the human carcinogen formaldehyde from pathology laboratories is possible even in contexts whereby commercial alternatives to formalin are unavailable or are too expensive for routine use, and aspiration devices are lacking or not adequately serviced. The use of known formulations, possibly with simple and not-noxious (“alimentary grade”) constituents, comparable with registered proprietary products, may expand the search for the ideal fixative combining satisfactory morphology with improved preservation of nucleic acids and proteins as well as being easy and safe to dispose of.

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Section: Resultscontrasting

confidence: 99%

Evaluation of two commercial and three home-made fixatives for the substitution of formalin: a formaldehyde–free laboratory is possible

et al. 2012

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“…Kap et al report an increase in intensity of goblet cell staining in PAS of intestinal samples in Paxgene-fixed samples [26]. Similarly, Moelans et al reported that while FineFix, RCL2 and F-Solv gave adequate staining for PAS, PASD, Alcian Blue and a number of others, fixation in NBF and standard pre-optimised techniques were superior [27].…”

Section: Effect Of Molecular Fixatives On Downstream Processesmentioning

confidence: 97%

Tissue fixation and the effect of molecular fixatives on downstream staining procedures

Howat

Wilson

2014

Methods

228

185

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It is impossible to underplay the importance of fixation in histopathology. Whether the scientist is interested in the extraction of information on lipids, proteins, RNA or DNA, fixation is critical to this extraction. This review aims to give a brief overview of the current “state of play” in fixation and focus on the effect fixation, and particularly the effect of the newer brand of “molecular fixatives” have on morphology, histochemistry, immunohistochemistry and RNA/DNA analysis. A methodology incorporating the creation of a fixation tissue microarray for the study of the effect of fixation on histochemistry is detailed.

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“…Moreover, SurePath contains a low concentration of formaldehyde added to the alcohol fixative to ensure adequate preservation of the cell material whereas ThinPrep uses methanol as the sole fixative. The difference in fixative has been a source of discussions internationally, with the claim that HPV analysis on SurePath samples can be challenged by the cross-linking between DNA and proteins driven by the formaldehyde content (42,43).…”

Section: Discussionmentioning

confidence: 99%

Clinical validation of full genotyping CLART® HPV4S assay on SurePath and ThinPrep collected screening samples according to the International Guidelines for Human Papillomavirus Test Requirements for Cervical Screening

Ejegod

Lagheden

Bhatia

et al. 2020

Preprint

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Background To ensure the highest quality of human papillomavirus (HPV) testing in primary cervical cancer screening, novel HPV assays must be evaluated in accordance with the international guidelines. Furthermore, HPV assay with genotyping capabilities are becoming increasingly important in triage of HPV positive women in primary HPV screening. Here we evaluate a full genotyping HPV assay intended for primary screening.Methods The CLART® HPV4S (CLART4S) assay is a newly developed full-genotyping assay detecting 14 oncogenic (16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, 68) and two non-oncogenic HPV genotypes (6, 11). It was evaluated using SurePath and ThinPrep screening samples collected from the Danish and Swedish cervical cancer screening programs, respectively. For calculation of sensitivity, 81 SurePath and 80 ThinPrep samples with confirmed ≥CIN2 were assessed. For clinical specificity analysis, 1,184 SurePath and 1,169 ThinPrep samples from women with <CIN2 histology were assessed. Sensitivity and specificity of the CLART4S assay was compared to an established reference test; the MGP-PCR (Modified General Primers GP5+/6+ with genotyping using Luminex). Inter and intra laboratory reproducibility of the assay was assessed using 540 SurePath and 520 ThinPrep samples, respectively. The genotype concordance between CLART4S and MGP-PCR was also assessed.Results In SurePath samples, the sensitivity of CLART4S was 0.90 (MGP-PCR =0.93) and the specificity was 0.91 (MGP-PCR=0.91); In ThinPrep samples the sensitivity of CLART4S was 0.98 (MGP-PCR=1.00) and specificity was 0.94 (MGP-PCR =0.87). The CLART4S was shown to be non-inferior to that of MGP-PCR for both sensitivity (p=0.002; p=0.01) and specificity (p=0.01; p=0.00) in SurePath and ThinPrep samples, respectively. Intra-laboratory reproducibility and inter-laboratory agreement was met for both media types. The individual genotype concordance between CLART4S and MGP-PCR was good agreement for almost all 14 HPV genotypes in both media types.Conclusions The CLART4S assay was proved non-inferior to the comparator assay MGP-PCR for both sensitivity and specificity using SurePath and ThinPrep cervical cancer screening samples from the Danish and Swedish screening programs, respectively. This is the first study to demonstrate clinical validation of a full-genotyping HPV assay conducted in parallel on both SurePath and ThinPrep collected samples.

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Formaldehyde Substitute Fixatives

Cited by 51 publications

References 24 publications

Evaluation of two commercial and three home-made fixatives for the substitution of formalin: a formaldehyde–free laboratory is possible

Evaluation of two commercial and three home-made fixatives for the substitution of formalin: a formaldehyde–free laboratory is possible

Tissue fixation and the effect of molecular fixatives on downstream staining procedures

Clinical validation of full genotyping CLART® HPV4S assay on SurePath and ThinPrep collected screening samples according to the International Guidelines for Human Papillomavirus Test Requirements for Cervical Screening

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