Deep UV Raman spectroscopy for probing active eukaryotic viruses

Deep Ultraviolet Resonance Raman Spectroscopy (DUVRR) is an emerging and powerful analytical tool used for detection and characterization of biological samples in a label-free and real time approach.

The excitation in the Deep UV provides specific resonance enhancement of biological moieties, especially protein, DNA and RNA structures, allowing to efficiently detect biological Raman markers in the spectra.

It is well known that DUV radiation is a genotoxic agent. Prolonged UV light exposition induces damage to the genomes of viruses, breaking bonds and forming photodimeric lesions in RNA.

These damages prevent both transcription and replication which leads to viral inactivation. Even though the effects of UV radiation on DNA of microorganisms have been well-recorded, its impact on RNA and RNA modifications is less known.

A sample that is prone to such a damage are viruses, and with the SARS-COV-2 (RNA virus) outbreak, the need of fast tools for viral characterization and classification became even more necessary.

In this work, we will show how to obtain stable, high quality and information-rich DUVRR spectra of active Vesicular Stomatitis Virus (VSV) without affecting its viability, RNA and protein integrity.

By opportunely tuning the excitation wavelength, we can detect and assign in the vibrational spectra specific markers of protein and RNA components useful to elucidate biochemical characteristics of active VSV virus.

In addition, we can study the effect of DUV irradiation in the mechanism of inactivation of VSV viruses in order to find the most damaging wavelength for the active VSV virus. This information can further be exploited to build an effective countermeasure tool for virus deactivation.

Speaker: Denis Rajnovic, ICGEB – Elettra Sincrotrone Trieste