Abstract. The scope of this thesis was the development of an advanced web application for searching and presenting biological information. The application concerns the research surrounding microRNA molecules which are studied for their effects on the function of the living organ-isms with great interest in the past few years. More specifically, researchers - biologists are interested in knowing the biological targets of the specific molecules onto the molecules that code proteins, so that they can arrive at useful conclusions which can give solution for different diseases. The preparation of the thesis was realized in cooperation with the Biomedical Sciences Research Center "Alexander Fleming", which has developed a suitable algorithm for predicting such targets. Moreover, the application provides personalization services, which aim to improve the user experience. These services comprise of history keep-ing of searches and the ability to save and edit favorite searches into the user's personal space. The application's development followed modern techniques and methodologies, such as the use of the Model - View - Controller architectural pattern and the use of unit testing, so that it facilitates the subsequent maintenance and upgrade of the capabilities offered.