Producing RNA chips for research purposes

DNA and RNA are nucleic acids; their best-known functions in cells are the long-term storage of genetic information in the form of DNA, and RNA as an intermediate in the biosynthesis of proteins. Commercially available DNA microarrays are used as standard to carry out high-throughput genome analyses. They are regularly used, for example, in the diagnosis of various hereditary diseases and cancer. They consist of a solid carrier, for example a small glass plate, on which a large number of different DNA molecules are bound. The special feature is that the exact position of each of these variants on the surface is known. On the other hand, they can be densely packed, so that hundreds of thousands of different DNA strands can fit on a surface the size of a thumbnail.

RNA chip production

The commercial production of DNA chips is based on the step-by-step concatenation of individual DNA building blocks. Although this production method has long been established, it can only be applied to the synthesis of RNA microarrays to a limited extent. This is because RNA molecules are much more unstable. The individual RNA building blocks also bind to each other less efficiently than their DNA equivalents when building the RNA strand. This effect limits the possible length of the RNA strand. „However, in order to investigate the as yet unknown functions of cellular RNA molecules in particular, chips with significantly longer RNA strands are required than were previously achievable with the chemical synthesis of RNA microarrays. Our new method now solves this problem“, explains first author Erika Schaudy, a young scientist in Mark Somoza's group at the Institute of Inorganic Chemistry at the University of Vienna.

Targeted use of enzymes

As the Viennese research team has now shown, the DNA sequences present on commercial chips can be transcribed into their complementary RNA strands by the targeted use of enzymes. Further enzymes then selectively degrade the DNA templates, resulting in an RNA chip. „The outstanding thing is that the production method we have developed is based solely on commercially available materials and reagents. Specialised laboratory equipment is not necessary. This now enables researchers from a wide range of disciplines to produce their own RNA microarrays that are precisely tailored to their scientific questions,

says a delighted Erika Schaudy.

Mark Somoza, who also heads a working group at the Leibniz Institute for Food Systems Biology at the Technical University of Munich in Freising, adds: "With this fast and easy-to-perform method, we have also created an important basis for further possible applications. For example, the RNA technology could also help to investigate the influence of food ingredients on cellular processes and therefore human health.

First author Erika Schaudy from the Institute of Inorganic Chemistry at the Faculty of Chemistry of the University of Vienna was one of 14 young scientists selected to present their research as part of the „Next Gen Science Session“ at the recently concluded Lindau Nobel Laureate Meeting 2022. Her talk on 27 June entitled „Light-Directed Synthesis of Complex Nucleic Acid Libraries“ can be viewed at: www.mediatheque.lindau-nobel.org/videos/39753/next-gen-science/meeting-2022

Source: LABO vom 04.11.2022