For blister, lesion, or vesicle, unroof and scrape the base of the lesion with a Dacron or rayon swab to collect fluid and cells. Place the swab into M4-RT transport medium. Ideally specimens should be collected within 3-4 days of the onset of symptoms but no greater than 7 days. Specimens collected from lesions in the acute or vesicular stage will yield a higher number of viruses. Avoid contamination with creams, ointments, lotions, alcohol, Betadine solution or blood due to the potential for PCR inhibition. Transport within 48 hours of collection at room temperature or refrigerated. If delivery to the laboratory will be delayed >48 hours, freeze specimen at less than or equal to 20 degrees Celsius. Do not allow frozen specimens to thaw; transport as soon as possible. Calcium alginate swabs are not acceptable.