Laboratory Detection of Respiratory Viruses by Automated Techniques

Pérez-Ruiz, Mercedes; Pedrosa-Corral, Irene; Sanbonmatsu-Gámez, Sara; Navarro-Marí, José-María

Recently, the goal of automation in these type of diagnostic tools has been achieved by a new commercial assay, the mariPOC ® respi test (ArcDia, Turku, Finland). This allows rapid detection and differentiation between viral and bacterial respiratory infections (Flu A, Flu B, RSV, hMPV, PIV 1, PIV2, PIV3, ADV and Streptococcus pneumoniae). The test is very simple to operate and handson-time is less than a minute per sample. Results for highly positive samples are obtained in 20 minutes whereas low positive and negative samples are reported in 2 hours. The mariPOC ® system uses polystyrene microparticles as solid phase reaction carriers for the immunocomplex formation. Viral antigens are captured by specific antibodies fixed onto the microsphere and bind to a fluorescentlylabelled conjugate. The amount of immunocomplexes formed on the microsphere is proportional to the analyte concentration. Detection of the fluorescence signal is carried out by separation-free two-photon excitation fluorescence detection assay, the ArcDia TM TPX (TPX). In contrast to other antigen detection methods, TPX assay avoids the need for multiple washes, and readout is achieved by on-line monitoring of reaction kinetics [26] . Preliminary studies have reported a sensitivity and specificity of this method comparable to ultrasensitive fluorescent immunoassays (DELPHIA ® method) [27, 28] and offers the advantage of automated result readout, allowing connections to laboratory information systems.