Valdiglesias, VanessaLaffon, BlancaAzqueta, AmayaFernández-Bertólez, NataliaPásaro, Eduardo2026-01-152026-01-152021-03-31FERNÁNDEZ-BERTÓLEZ, Natalia, et al. Salivary leucocytes as suitable biomatrix for the comet assay in human biomonitoring studies. Archives of toxicology, 2021, vol. 95, no 6, p. 2179-2187.1432-07380340-5761https://hdl.handle.net/2183/46905This is an accepted version of the following published document: Fernández-Bertólez N, Azqueta A, Pásaro E, Laffon B, Valdiglesias V (2021) Salivary leucocytes as suitable biomatrix for the comet assay in human biomonitoring studies. Arch Toxicol 95(6):2179–2187. https://doi.org/10.1007/s00204-021-03038-8 This version of the article has been accepted for publication, after peer review (when applicable) and is subject to Springer Nature’s AM terms of use, but is not the Version of Record and does not reflect post-acceptance improvements, or any corrections. The Version of Record is available online at: https://doi.org/10.1007/s00204-021-03038-8[Abstract] Peripheral blood leucocytes (PBL) have been traditionally used to investigate DNA damage by the comet assay in population studies, but validating alternative non-invasive samples would expand the application of this assay in human biomonitoring. The objectives of this study were (i) to test the validity of salivary leucocytes as a proper biomatrix for the comet assay, (ii) to evaluate the ability of this approach to detect different types of primary and oxidative DNA damage, and (iii) to determine whether frozen salivary leucocytes are still suitable for displaying those types of DNA damage. Fresh and frozen leucocytes isolated from saliva samples (six healthy non-smoking volunteers), were exposed to four genotoxic agents inducing different types of DNA damage, both primary (methyl methanesulfonate, actinomycin-D, ultraviolet radiation) and oxidative (potassium bromate), and standard or enzyme-modified comet assay was conducted. Results were compared with those obtained from PBL. Cells exposed to the four genotoxic agents showed dose-dependent increases of primary and oxidative DNA damage, demonstrating the suitability of all these samples to detect genetic damage from different origin. When comparing baseline levels of DNA damage, just a slight significant increase in primary DNA damage was observed in frozen salivary leucocytes regarding the other biomatrices, but similar results were obtained regarding sensitivity to DNA damage induction by all agents tested. This study demonstrates that salivary leucocytes can be employed in comet assay as an alternative or complement to blood samples. Frozen salivary leucocytes were proved to be a very convenient sample in large biomonitoring studies.eng© The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2021Comet assayFrozen samplesHuman biomonitoringSalivary leucocytesjournal articleopen access10.1007/s00204-021-03038-8