1. Nucleic Acid Extraction and quantitative reverse transcription polymerase chain reaction or qRT-PCR Detection
- Isolate nucleic acids directly from anion exchange resin and, for comparative purposes, from the liquid used within the liquid impingers. In this example, an RNA isolation procedure is described, but a similar protocol could be used for DNA viruses.
- Nucleic acid isolation from the anion exchange resin.
- Transfer all of the anion exchange resin-containing liquid of the liquid impinger to a sterile 50 mL conical tube.
- Allow the resin to settle, and slowly decant the liquid sample from the anion exchange resin. Use a 1 mL pipette tip to remove all of the remaining liquid from the anion exchange resin.
- From a viral RNA isolation kit, add 560 µL of viral lysis buffer containing carrier RNA directly to the anion exchange resin and incubate for 10 min at room temperature with periodic mixing.
- Using a 1 mL pipette tip, transfer the viral lysate (the viral lysis buffer) to a sterile 1.5 mL conical tube and proceed with RNA isolation using a viral RNA isolation kit (see Table of Materials) in accordance with the manufacturer's instructions, except that RNA is eluted in a total volume of 60 µL of elution buffer.
- Nucleic acid isolation from liquid impingers.
- Pipette 140 µL of the liquid sample into a sterile 1.5 mL conical tube and perform RNA isolation using the viral RNA isolation kit in accordance with the manufacturer's instructions, with the exception of eluting RNA in a total volume of 60 µL of elution buffer.
NOTE: 140 µL is the maximum sample volume that can be processed with the specific viral RNA isolation kit employed here in a single-step preparation.
- Perform qRT-PCR (quantitative Reverse Transcription Polymerase Chain Reaction) for the detection of Male-specific 2 (MS2) fRNA coliphage and influenza A and B viruses. In this demonstration, 5 µL of nucleic acid eluates are used for qRT-PCR.