Comparison of Different Kits for SARS-CoV-2 RNA Extraction Marketed in Brazil

ABSTRACT December 2019 marked the begining of the greatest pandemic since Spanish Flu, the disease named Covid-19 that cause severe pneumonia. Until May 19, 2020 more than 4 million and 700 thousand cases were oficially notified with about 316 thousand deaths. Etiological agent of the disease was identified as being a new coronavirus, Severe acute respiratory syndrome-related coronavirus (SARS-CoV-2). In this study we compared four different manual methods for RNA isolation and purification for detection of SARS-CoV-2 through qRT-PCR, as well as the extraction quality itself through detection of RNAse P. Magnetic beads-based (MagMax™) and silica column-based (Biopur ® ) methods presented the better performances. Concerning to the mean delay in CT values when compared to MagMax™, TRIzol™, Biopur ® and EasyExtract presented 0,39, 0,95 and 5,23 respectively. Agreement between positive and negative results of different methods when compared with the one with better performance MagMax™ was 94,44% for silica column-based method (Biopur®), 88,89% for phenol-chroloform-based method (TRIzol™) and 77,78% for EasyExtract. We aimed to evaluate how reliable each method is for diagnostic purposes and to propose alternatives when usual methods are not available. In this regard, magnectic beads and silica column-based methods are convenient and reliable choices and phenol-chloroform-based method could also be chosen as an alternative.