Exfoliated cells from the buccal mucosa are a promising source of genomic DNA (Borthakur et al., 2008, Shimizu et al., 2022). DNA from oral cells can be used for various purposes such as monitoring cancer (Cortés-Gutiérrez et al., 2021) and DNA damages (Alabi et al., 2020, Bhagwath and Chandra, 2014). These cells can be obtained non-invasively, painlessly, and quickly, which ensures easy acceptance by individuals who can also perform self-collection. Additionally, buccal mucosa exfoliated cells can be collected multiple times over time. The collection procedure can be performed in two ways: dry brushing or using liquid rinse (García-Closas et al., 2001, Huang et al., 1999, Kim et al., 2022).

The dry method is simple, cost-effective, yields sufficient quantity and quality of DNA for genotyping. Furthermore, samples collected by this method showed lower sensitivity to long-term storage effects. Dry collection of oral cells can be carried out using cytological brushes or cotton swabs, yielding a similar amount of DNA in both cases (King et al., 2002, Ambroa-Conde et al., 2022).

After collection, DNA extraction can be performed immediately or the sample can be stored for different periods of time. However, DNA degrades with increasing time and temperature. Ideally, it should be isolated shortly after collection, cryopreserved, or stored in preservation media (Alaeddini et al., 2010, Woo and Lu, 2019). Notwithstanding, in many situations, immediate access to the necessary equipment may not be available, and commercially available preservation cards and solutions are costly, which can hinder their use in epidemiological studies or large-scale population studies (Harvey, 2006, Reeve et al., 2018, Woo and Lu, 2019). In this regard, the use of cost-effective laboratory-formulated DNA preservation solutions that ensure the viability of buccal mucosa exfoliated cells is a promising alternative in the field. Therefore, the objective of this study is to compare the DNA preservation capacity of buccal mucosa exfoliated cells that were kept in different solutions under varying time and temperature conditions.