Outer Limits of Flow Cytometry to Quantify Viruses in Water

• DOI: 10.1021/acsestwater.0c00113
• Publication Date: 2021-03-08T13:54:22Z
• Authors: Elena Dlusskaya; Rafik Dey; Peter C. Pollard; Nicholas J. Ashbolt
• Keywords: flow virometry results; prototype flow cytometer; 0301 basic medicine; Ecology; FCM; SYBR Green dye colloid; Plant Biology; virus; flow virometry; 3. Good health; 03 medical and health sciences; Infectious Diseases; Space Science; Virology; Genetics; Medicine; Rigorous background controls; Biotechnology; Cancer

The use of flow cytometry (FCM) with environmental or clinical samples to enumerate viruses (flow virometry) has become popular the development sensitive fluorescent dyes that bind nucleic acids, yet there is no quantitative evidence sensitivity and accuracy for virometry as applied aquatic environments. Rigorous background controls are missing. Here we address gap in our knowledge how interferes interpreting results. To remove interference, discovered it was essential separate from their water matrix resuspended them virus free Tris-EDTA buffer. Background substances a SYBR Green dye colloid produce "virus-like" artifacts generate false-positive viral counts. We show neither human enteric nor bacteriophage surrogates small genome size (<150 kbp) can be detected using standard FCM. concluded current accurate enough quantify most natural populations recommend improved procedures unambiguously proving FCM signal indeed viral. However, still limited by inability instruments detect viruses, other methods example prototype cytometer developed nanomaterials (with throughput 10000 per minute) could have potential online monitoring abundance both engineered