Popular Science: Easy, quick and affordable – a new method of (not only) cancer diagnosis
The scientists focused on detecting three indicators – homovanilic acid, vanilmandelic acid and 5-hydroxyindol-3-acetic acid. High secretion of those acids can indicate children’s brain tumours, rare adrenal glands tumours and many others. Abnormal levels of those indicators can also be caused by other diseases. They have been linked to Parkinson disease, schizophrenia, suicidal attempts and posttraumatic stress disorder.
These indicators are usually detected in urine using various methods, which usually require lengthy, difficult and expensive processing of the sample before the analysis. In addition, the vast majority of these methods are not able to detect all three substances at the same time.
Professor Barek’s team therefore focused on developing a quick and affordable method by using high performance liquid chromatography (a method of separating substances based on their different distribution between two different phases which move relative to each other) connected with highly sensitive amperometric detection (a detection method using the electric current originating from electrochemical transformation of these substances). By using a simple laboratory arrangement, the scientists managed to detect all three desired substances in one run without the need for complex preparation of the sample. The separation of the substances took about 10 minutes in contrast to 20 minutes with the other methods that are used today. They were also able to detect sufficiently low concentrations of all of the substances.
To verify the method’s validity, a healthy human’s urine with all the levels known was analysed. The results obtained using the new method corresponded with the assumptions. The practical applicability of the new method was tested by analysing a spiked urine sample. The goal was to detect higher levels which turned out to be the case.
The newly developed method has a number of advantages right from the preparation of the sample before the actual analysis. In addition to being easier and faster, the process can also be automated so that several samples can be prepared at the same time. It is also more environmentally friendly due to the lower use of organic solvents which require special disposal. The separation itself is about twice as fast as the current methods which also makes it more ‘green’ and less expensive thanks to lower material usage. The final detection is much less costly than the previously developed methods and it is also more selective as it is not disturbed by most of the other substances found in urine.
This method can therefore be used to simply and affordably test urine samples and it can contribute to an early diagnosis of cancer and other diseases.
Makrlíková-Němečková, Anna & Barek, Jiri & Navrátil, Tomáš & Fischer, Jan & Vyskočil, Vlastimil & Dejmková, Hana. (2020). Simultaneous Determination of Tumour Biomarkers Homovanillic Acid, Vanillylmandelic Acid, and 5-Hydroxyindole-3-acetic Acid in Human Urine Using Single Run HPLC with a Simple Wall-Jet Glassy Carbon Electrochemical Detector. Journal of Electroanalytical Chemistry. 878. 114629. 10.1016/j.jelechem.2020.114629.