Once you’ve collected your sample, put the tube in the biohazard bag included with your kit. (The tube should go inside the rigid plastic insert in the biohazard bag.) Seal the bag.
Put the biohazard bag in the return shipping bag. Seal the bag. Drop your sample at a USPS mailbox or post office. Samples should be put in a mailbox mailed to the laboratory within 24 hours of collection.