Suitability of an automated nucleic acid extractor (easyMAG) for use with hepatitis C virus and human immunodeficiency virus type 1 nucleic acid amplification testing

Comparison of procedures for RNA-extraction from peripheral blood mononuclear cells

RNA quality and quantity are important factors for ensuring the accuracy of gene expression analysis and other RNA-based downstream applications. Thus far, only a limited number of methodological studies have compared sample storage and RNA extraction procedures for human cells. We compared three commercially available RNA extraction kits, i.e., (NucliSENS) easyMAG, RNeasy (Mini Kit) and RiboPure (RNA Purification Kit–blood). In addition, additional conditions, such as storage medium and storage temperature of human peripheral blood mononuclear cells were evaluated, i.e., 4 °C for RNAlater or -80 °C for QIAzol and for the respective cognate lysis buffers; easyMAG, RNeasy or RiboPure. RNA was extracted from aliquots that had been stored for one day (Run 1) or 83 days (Run 2). After DNase treatment, quantity and quality of RNA were assessed by means of a NanoDrop spectrophotometer, 2100 Bioanalyzer and RT-qPCR for the ACTB reference gene. We observed that high-quality RNA can be obtained using RNeasy and RiboPure, regardless of the storage medium, whereas samples stored in RNAlater resulted in the least amount of RNA extracted. In addition, RiboPure combined with storage of samples in its cognate lysis buffer yielded twice as much RNA as all other procedures. These results were supported by RT-qPCR and by the reproducibility observed for two independent extraction runs.

Comparison of the new fully automated extraction platform eMAG to the MagNA PURE 96 and the well-established easyMAG for detection of common human respiratory viruses

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.

In all categories tested, eMAG results were comparable to those of the easyMAG and MagNa PURE 96, highly sensitive for all viruses and over 98% clinical specificity and sensitivity for all viruses tested. Together with its high level of automation, the bioMerieux eMAG is a high-quality extraction platform enabling effective molecular analysis and is mostly suitable for medium-sized laboratories.