Should I refrigerate my specimen before mailing?

If you collect your specimen in the morning but cannot mail it until later in the day, you may refrigerate it (4°C, standard refrigerator temperature) for up to 24 hours before mailing. Do NOT freeze the specimen. With the preservation media added, the specimen is stable at ambient temperature for up to 72 hours — so refrigeration is precautionary rather than required for short delays. If you collect on a Thursday and cannot mail until Friday, refrigerate overnight and mail first thing Friday morning — but be aware of the holiday and weekend shipping restrictions.