Salvatore Marras received his B.S. degree in biotechnology, and received his doctoral degree in molecular genetics from the Department of Molecular Cell Biology at Leiden University, the Netherlands, in the laboratory of Professor Hans J. Tanke, who is a pioneer in the nucleic acid hybridization field.
The focus of his research has been the development of fluorogenic probes for nucleic acid detection in amplification reactions, and in live and fixed cells. He contributed to molecular beacons technology by establishing the thermodynamic parameters for their design, by studying the mechanism of fluorescence energy transfer between their labels, and by developing wavelength-shifting molecular beacons. In addition, he has co-authored more than twenty publications that describe the detection and identification of pathogens and genotypes using nucleic acid amplification methods that utilize single nucleotide polymorphism specific molecular beacons, mismatch tolerant molecular beacons, and / or sloppy molecular beacons.
Education
PHD, 2003, Leiden, The Netherlands, Not Available BS, 1994, Niejmegen, The Netherlands, Not Available
Relevant Publications
Marras SAE, Chen L, Shashkina E, Davidson RM, Strong M, Daley CL, Kreiswirth BN (2021) A Molecular-Beacon-Based Multiplex Real-Time PCR Assay To Distinguish Mycobacterium abscessus Subspecies and Determine Macrolide Susceptibility. J Clin Microbiol 59: e0045521. PMI: 33980653
Marras SAE, Bushkin Y, Tyagi S (2019) High-fidelity amplified FISH for the detection and allelic discrimination of single mRNA molecules. Proceedings of the National Academy of Sciences USA 128: 13921???13926. PMI: 31221755
Vargas DY, Marras SAE, Tyagi S, Kramer FR (2018) Suppression of wild-type amplification by selectivity enhancing agents in PCR assays that utilize SuperSelective primers for the detection of rare somatic mutations. Journal of Molecular Diagnostics 20: 415-427. PMI: 29698835
Vargas DY, Kramer FR, Tyagi S, Marras SAE (2016) Multiplex real-time PCR assays that measure the abundance of extremely rare mutations associated with cancer. PLoS One 11: e0156546. PMI: 27244445
El-Hajj HH, Marras SAE, Tyagi S, Shashkina E, Kamboj M, Kiehn TE, Glickman MS, Kramer FR, Alland D (2009) Use of sloppy molecular beacon probes for identification of mycobacterial species. Journal of Clinical Microbiology 47: 1190-1198. PMI: 19171684
Marras SAE, Kramer FR, Tyagi S (2002) Efficiencies of fluorescence resonance energy transfer and contact-mediated quenching in oligonucleotide probes. Nucleic Acids Research 30: e122. PMI: 12409481
Marras SAE, Kramer FR, Tyagi S (1999) Multiplex detection of single-nucleotide variations using molecular beacons. Genetic Analysis: Biomolecular Engineering 14: 151-156.: PMI: 10084107
Development of fluorescent nucleic acid hybridization probes
The introduction of self-quenching fluorescent nucleic acid hybridization probes has markedly improved the
ability to detect RNA and DNA sequences with high sensitivity and specificity. Self-quenching probes are useful in
situations where it is not possible or desirable to separate probes that are not hybridized to target sequences
from probes that are hybridized to target sequences. Examples are: real-time polymerase chain reactions (PCR)
and nucleic acid sequence-based amplification (NASBA) assays, and the detection of DNA and RNA targets in
living cells.
Together with his colleagues, Fred Russell Kramer and Sanjay Tyagi, Salvatore Marras developed molecular
beacons, one of the first fluorescent nucleic acid hybridization probe technologies. His research focuses on the
different properties of fluorescent hybridization probes, such as design parameters that affect their specificity,
and on the effects of interactions between different fluorophore-quencher pairs. His group also develops novel
nucleic acid detection methods, including: self-reporting DNA microarray platforms; highly multiplexed, real-time
nucleic acid amplification assays for the detection of infectious agents in clinical samples; and extremely sensitive
in situ and in vivo hybridization methods, utilizing organic-based fluorescent reporters and metal-based
luminescent compounds.
