Genotyping of CYP2C9 using DNA from hair roots, saliva, fingernails, buccal cell swabs and blood / Maznuraini Zainuddin

Background: Blood is an excellent source of genomic DNA. However, blood sampling is invasive, painful and requires complicated handling and transport. Therefore, we intend to obtain DNA from other sources such as hairs, saliva, fingernails and buccal cell as an alternative to blood. The samplings of these non-blood specimens are painless, non-invasive, convenient and accessible as compared to blood as a source of DNA for genotyping test. Aim: The aim of the study was to develop a simple DNA extraction method from sources other than blood. These DNA could thus be used for genotyping test of the polymorphic CYP enzymes whereby CYP2C9*3 was used as prototype. Method: Hairs, saliva, fingernails, buccal cell swabs and blood were taken from 5 healthy unrelated volunteers. They are students of Faculty of Pharmacy, Universiti Teknologi MARA. The samples were subjected to DNA extraction. DNA were extracted from hair roots, saliva, fingernails, buccal cell swabs by using 2 different extraction methods which were one step DNA extraction method with and without Chelex. The blood samples were extracted by using Quick Gene DNA whole blood kit S (DB-S). The extracted DNA was used for subsequent PCR based genotyping of CYP2C9*3. Results: DNA was successfully extracted from hair roots, saliva, fingernails and buccal cell swabs by using both extraction methods. However, the amount of DNA extracted was not as high yield as compared to DNA extracted from blood. The DNA obtained from these different sources were able to be amplified by PCR and thus useful for genotyping of CYP2C9*3 in comparison to DNA extracted from blood. Conclusion: The DNA extracted from hair roots, saliva, fingernails and buccal cell swabs were useful sources of genomic DNA and thus could be used in genotyping of CYP2C9*3.