How to take an ulcer/blister sample for a herpes test

A herpes test can be taken only during the period when there is a blister or ulcer (open sore) caused by herpes infection. The test must not be taken when the blister rash is healing, i.e. is covered by callus, since at that moment, there may be no virus present in the ulcer and the test may yield a false (false negative) result.

  • For taking the ulcer or blister sample, the kit contains a plastic tube with a swab attached to the cap (a thin plastic tube with a cotton swab).
  • Before taking the sample, wash your hands thoroughly. Remove the cap with the cotton swab attached to it from the tube.
  • With the end of the cotton swab, scrape the bottom of the ulcer 4-8 times, or collect the liquid from the blister(s) onto the swab.
  • Then place the swab back into the tube and write the date of taking the sample onto the tube.
  • Place the tube into the plastic bag provided with the kit and put it into the envelope.
  • Close the safety envelope carefully.