Evaluation of ExiPrep16 Automated System for the Extraction of Nucleic Acids from Nasopharyngeal Swabs for the Detection of Respiratory Viruses

ABSTRACT

BACKGROUND: Automated nucleic acid extraction offers a standardized sample treatment method, low error rate, and avoids sample nucleic acid contamination for use in molecular diagnostics. Here, we evaluated the performance of automated ExiPrep16 system (Bioneer Co.) in comparison with the manual Viral Gene-spin Viral DNA/RNA Extraction kit (VGspin; iNtRON Biotechnology Inc.) for the detection of respiratory viruses from nasopharyngeal flocked swabs. METHODS: To compare the agreement rate and analytical sensitivity between ExiPrep16 and VGspin, previously collected 78 patient samples and 11 pooled samples of each respiratory viruses and their serially diluted samples (until 1/10(8)), were tested by multiplex reverse-transcriptase PCR (Seeplex RV 12 ACE Detection kit; SeeGene Inc.). In addition, we repeatedly analyzed the threshold cycle of the pooled and 1/10(3) dilution of adenovirus (ADV) and influenza virus A (Flu-A) by using real-time PCR to evaluate the precision and crossover of the ExiPrep16 system. RESULTS: The analytical sensitivity of the ExiPrep16 was comparable to that of VGspin, and the highest detectable dilution varied in the range of 1/10 to 1/10(6) depending on the viruses. The total, overall positive and negative percent agreements of ExiPrep16 in comparison with VGspin were 95.7%, 96.2%, and 95.2%, respectively. The mean (CV%) of pooled and 1/10(3) dilution of ADV were, respectively, 19.2 cycle (2.1%) and 31.6 cycle (4.3%) and those for Flu-A were 22.6 cycle (3.1%) and 35.5 cycle (2.6%). No carryover was detected. CONCLUSIONS: Compared to the manual VGspin, ExiPrep16 ensured nucleic acid extraction for efficient detection of respiratory viruses.