How to check if your dog is not human? DNA research by Gdańsk scientists

Albert, who became an inspiration for the Gdańsk scientists' research, is a dog of prof. Jacek Ryla from the Faculty of Technical Physics and Applied Mathematics, PG.

'Albert is a dog, but he doesn't realise it. Albert loves human food (and beer), watching videos on the internet, sleeping in bed and more, but he's not supposed to do all those things. To convince him of this, we developed a test procedure to resolve this doubt.' - With these words begins the introduction to the publication of a team of scientists from the University of Gdańsk, Gdańsk University of Technology and Gdańsk Medical University, who developed a test that allows for quick detection of DEFB1 gene, unique for humans. The solution may prove useful in diagnostics and forensic medicine in the analysis of DNA samples of unknown origin.

The prestigious journal Sensors & Actuators: B. Chemical published the results of research by a team of scientists forming the Association of Fahrenheit Universities, including employees of the University of Gdańsk, Gdańsk University of Technology and Gdańsk Medical University. They developed a method for rapid detection of the DEFB1 gene, unique for the human species, in a saliva sample. They were helped by Albert, a dog who loves human food, films on the Internet and sleeping in bed.

The main advantage of the developed method is the reduction of the time needed to analyse DNA samples in comparison to the currently used method of determining the human genome, (by polymerase chain reaction - PCR), based on the duplication of genetic material.

In the method used, not only the ability to modify the electrode surface in order to determine the beta-defensin 1 gene (DEFB1) in saliva samples from animals and man was exploited, but also the analytical technique based on the analysis of changes occurring on the electrode, based on monitoring of momentary changes in the impedance of the system under study, which has not been used before, was applied. The analysed gene is present in the human genome and occurs only in human DNA. Therefore, the above-mentioned relationship was used to differentiate the tested samples using specially modified electrodes. Verification of the origin of the collected samples was carried out on specially modified diamond electrodes doped with boron, which show unique features compared to traditional electrodes, they have a low background current, making them ideal for this type of research. The electrodes used for the research were made in a team led by dr hab. inż. Robert Bogdanowicz, prof. PG from the Faculty of Electronics, Telecommunications and Informatics.

- 'Modification of the electrode surface with a specific oligonucleotide allowed to obtain a sensitive surface to track changes occurring on the electrode. This approach made it possible to detect and identify the gene under study by following the DNA hybridisation process' - says dr Paweł Niedziałkowski from the Faculty of Chemistry, University of Gdańsk.

- 'It is worth stressing that the applied measurement method based on the analysis of impedance spectra allows tracking changes occurring on the electrode in real-time, which is a great advantage in the process of binding DNA samples and is extremely important in the detection of such processes,' says dr hab. inż. Jacek Ryl, PG professor from the Department of Technical Physics and Applied Mathematics.

As the researchers emphasise, the developed measurement technique for detecting human DNA can be used in diagnostic studies for identifying DNA samples of various sizes for medical and forensic purposes.

Members of the research team: dr Paweł Niedziałkowski (Faculty of Chemistry, UG), dr hab. inż. Jacek Ryl, prof. uczelni (Faculty of Technical Physics and Applied Mathematics, PG), dr inż. Joanna Wysocka (Faculty of Chemistry, PG), prof. dr hab inż. Tadeusz Ossowski (Faculty of Chemistry, UG), dr hab. inż. Paweł Ślepski, prof. uczelni (Faculty of Chemistry, PG), dr hab. inż. Robert Bogdanowicz, prof. uczelni (Faculty of Electronics, Telecommunications and Informatics, PG), dr inż. Michał Sobaszek (Faculty of Electronics, Telecommunications and Informatics, PG), dr Joanna Charmier-Ciemińska (Forensic Biology and Genetics Laboratory, GUMed), dr Łukasz Burczyk (Faculty of Chemistry, PG), dr Anna Wcisło (Faculty of Chemistry, UG).

EMW/Press Office of University of Gdańsk