Concentrating Virus-Enriched Water Samples by Centrifugal Ultrafiltration

Take an environmental water sample containing enteric viruses.

Transfer an aliquot into the upper chamber of a centrifugal concentrator containing a semipermeable membrane.

The upper chamber is pretreated with a phosphate buffer containing blocking agents to prevent nonspecific binding.

Centrifuge at a low temperature to preserve viral integrity.

The semipermeable membrane retains viruses larger than the pore size while allowing smaller molecules to pass through.

Rinse the chamber walls with the phosphate buffer to release loosely attached viruses.

Centrifuge to reduce the buffer volume, then wash the chamber walls again with the phosphate buffer.

Centrifuge again to reduce the buffer volume, maximizing virus concentration.

Transfer the concentrated virus-rich supernatant to a fresh microcentrifuge tube and add buffer to adjust the final volume.

The concentrated viral suspension is now ready for downstream molecular analysis.

After preparing a standard curve according to the text protocol, prepare a centrifugal concentrator for each sample collected, by adding at least 10 milliliters of 1x PBS and 2% BSA to the upper sample chamber. After incubating overnight, washing, then adding the sample