Comparison of Manual and Automated Nucleic Acid Extraction Methods in Virus Transport Medium

The implementation of an automated nucleic acid extraction system has many advantages over the manual methods. The purpose of this study was to evaluate the validity of two different methods for nucleic acid extraction in virus transport medium.

We collected 20 nasopharyngeal swabs in viral transport medium from the emergency department of the Asia University Hospital for the detection of SARS-CoV-2. The performance of the MaelstromTM 8 (Taiwan Advanced Nanotech) and the QIAamp Viral RNA Mini Kit (Qiagen) were compared for the extraction of nucleic acid from viral transport medium. The extracts were used for the validation of the RNA extraction procedures. The RNase P target was amplified in a one-step reverse transcription-quantitative PCR (RT-qPCR) reaction, as internal control for the extraction method.

In this study, the agreement between the two methods was good and Pearson's correlation coefficient (r) was 0.919 (p < 0.001). The mean cycle threshold value of the two methods was 29.1.

Overall, the performance values of the MaelstromTM 8 and the QIAamp Viral RNA Mini Kit were comparable to each other. In summary, the MaelstromTM 8 provides a standardized procedure, avoidance of sample-to-sample cross contaminations, is easy to use, improves turnaround time and requires less hands-on time as compared to the manual extraction method. The MaelstromTM 8 is more suitable for clinical laboratories that carry small or medium-sized samples for nucleic acid extraction.