The use of the multiplex polymerase chain reaction (PCR) technique for respiratory viruses has become popular in Korea owing to its convenience and sensitivity. However, concerns remain with regard to possible interference due to multiplexing.

We compared the analytical sensitivity and virus interference of a commercially available, multiplex PCR kit (AdvanSure Respiratory virus real-time PCR kit, LG Life Sciences, Korea) with that of singleplex PCR to detect 11 viruses including coronavirus 229E and OC43; parainfluenza virus 1 (PIV 1), parainfluenza virus 2 (PIV 2), and parainfluenza virus 3 (PIV 3); influenza virus A (INF A) and influenza virus B (INF B); respiratory syncytial virus A (RSV A) and respiratory syncytial virus B (RSV B); adenovirus; and rhinovirus A, B, and C.

The lowest detected viral concentrations of coronavirus 229E and OC43, INF A and B, RSV A and B, adenovirus, and rhinovirus A, B, and C were the same for both, multiplex and singleplex systems. However, the lowest detected viral concentrations of PIV1, 2, and 3 differed by 1 dilution factor between the two systems. Threshold cycle (Ct) values for mixed viruses within the same well were not significantly influenced by each other, where the difference between Ct values ranged from 0.24 to 1.99.

Analytical sensitivity of multiplex PCR was comparable to that of singleplex PCR for respiratory viruses. No significant interference was observed with mixed virus samples using multiplexed PCR.