Evaluation of the applicability of viable quantitative real time-PCR (v-qPCR) to expedite viral penetration resistance assessment of personal protective equipment

Purpose In the USA, personal protective equipment (PPE) that claims to resist viral penetration, must pass the American Society for Testing and Materials (ASTM) F1671 test method which uses a standard plaque assay (SPA) to quantify Phi-X174 virus. SPA is labor-intensive, time-consuming, limiting its practicality for rapid screening. This study evaluates whether a viable quantitative Real-time Poly-merase Chain Reaction (v-qPCR), targeting two amplicon size (332bp, and 1644bp) can serve as a rapid screening tool for PPE during shortages. Design/methodology/approach Phi-X174 was subjected to heat and UVC treatments known to damage viral capsids and/or genomes. Samples were treated with propidium monoazide (PMA), and viral quantities were assessed using v-qPCR and SPA. Quantification outcomes from v-qPCR were compared against SPA titers. Findings v-qPCR targeting the 332 bp fragment produced quantification results consistent with SPA, with the greatest difference being about one order of magnitude (3.99×10ˆ10± 4.09×10ˆ9 Particle-Forming Unit/ml (PFU/ml) vs. 2.98×10ˆ9 ± 1.80×10ˆ9 PFU/mL). The v-qPCR method demonstrated a limit of detection of 500 viral copies for the 332 bp target. The 1644 bp amplicon showed higher variability and lower sensitivity. Originality/value This study is the first to assess v-qPCR's potential for PPE testing by evaluating amplicon size effects and comparing quantification to SPA under standardized damaging conditions. The results suggest that v-qPCR offers a practical screening alternative to support rapid PPE evaluation.