Date Published: February 19, 2019
Publisher: Public Library of Science
Author(s): Musa Hindiyeh, Orna Mor, Rakefet Pando, Batya Mannasse, Areej Kabat, Hadar Assraf-Zarfati, Ella Mendelson, Danit Sofer, Michal Mandelboim, Olivier Terrier.
Respiratory viral infections constitute the majority of samples tested in the clinical virology laboratory during the winter season, and are mainly diagnosed using molecular assays, namely real-time PCR (qPCR). Therefore, a high-quality extraction process is critical for successful, reliable and sensitive qPCR results. Here we aimed to evaluate the performance of the newly launched eMAG compared to the fully automated MagNA PURE 96 (Roche, Germany) and to the semi-automated easyMAG (bioMerieux, France) extraction platforms. For this analysis, we assessed and compared the analytic and clinical performance of the three platforms, using 262 archived respiratory samples positive or negative to common viruses regularly examined in our laboratory (influenza A, B, H1N1pdm, Respiratory Syncytial Virus (RSV), human Metapneumovirus (hMPV), parainfluenza-3, adenovirus and negative samples). In addition, quantitated virus controls were used to determine the limit of detection of each extraction method.
Respiratory viral infections are a major cause of morbidity and mortality worldwide  and have been shown to be the etiological agents of more than 70% of respiratory tract infections (RTIs) . Nucleic acid-based tests, mostly performed in multiplexes by real-time PCR (qPCR) platforms, are the most common and efficient means of detecting viral infections, and support rapid and simultaneous detection of many viruses [3,4]. The nucleic acids extraction process is one of the most significant steps dictating the accuracy and sensitivity of viral infection diagnosis and virus type determination. Moreover, efficient extraction allows for the detection of different viral agents including DNA and RNA viruses, from a single extraction tube. Using qPCR technology, the Israeli Central Virology Laboratory performs viral detection on more than 10,000 respiratory samples each year, which constitute the majority of samples requiring nucleic acid extraction process in our laboratory.
In the past few years, an increasing number of respiratory clinical samples have been examined in our laboratory, the Israeli Central Virology Laboratory, Ministry of Health. As our main “gold standard”, well established [12–14].extraction platform- the easyMAG can extract only 24 samples, we continuously seek to streamline the work and reduce the turnaround time. Therefore, we evaluated a larger platform- the eMAG, based on the same extraction technology as the easyMAG, which can extract up to 48 samples in each run. The eMAG was also compared with the well-validated MagNA PURE 96 that enables the extraction of 96 specimens, and currently present in our laboratory in order to evaluate the eMAG performance against another larger scale extraction platform.