Viral Penetration Test

Testing Locations

• Salt Lake City, UT, USA
• Fairfield, NJ, USA (Gibraltar Laboratories)
• Leuven, Belgium

Study Outline

In this Viral Penetration test procedure, specimens are prepared by randomly cutting the test material into approximately 75 mm x 75 mm swatches. The swatches are conditioned at 21 ± 5°C and 30 – 80% relative humidity for at least 24 hours. Once conditioned, individual test specimens are loaded into the penetration test cell with the outside of the material facing the reservoir. The test cell reservoir is then filled with approximately 60 ml of the phiX174 bacteriophage suspension, maintained at a concentration of at least 1.0 x 10⁸ plaque-forming units/mL, and allowed to sit for 5 minutes at atmospheric pressure.

After the initial 5 minutes, an external air source is connected to the test cell and a pressure of 2 pounds per square inch gauge (psig) is applied to the sample for 1 minute. After 1 minute of applied pressure, the pressure is released and the specimen then sits for an additional 54 minutes at atmospheric pressure.

Throughout the test, the surface of the specimen is observed for penetration. To further evaluate whether viral penetration occurred, at the end of the test, the surface of the test specimen is rinsed with a sterile assay fluid and collected. This assay fluid is plated using standard plaque assay techniques. The assay plates are then incubated for 6 – 18 hours. Specimens showing no plaques on any of the assay plates pass the test, while plates that exhibit plaque-forming units fail.

The surface tension range for blood and body fluids is approximately 42 – 60 dynes/cm. To simulate the wetting characteristics, the phiX174 bacteriophage suspension is adjusted to the lower end of this range (42 ± 2 dynes/cm).

If you have additional questions about Viral Penetration testing, or would like to consult with the experts at Nelson Labs, just send us a request or call us at +1 (801) 290-7500.