I continue to stand by that statement! First, NAATs are nearly universally employed by labs that offer postal delivery for gonorrhea, chlamydia, and others (e.g. trichomonas or M. gentalium). Second, DNA is exceedingly stable -- just think of all the media stories about identifying and analyzing DNA in long dead tissues. Third, when specimen management instructions advise things like 4 day arrival in the lab, refrigeration, or similar issues, that only means that these parameters were used in the pre-approval research and therefore accuracy cannot be guaranteed outside these standards. For example, if samples were tested at 4 days, or if always refrigerated after collection, the approved instructions must say the same thing. That doesn't mean that the test is otherwise unreliable, only that the test has not been studied outside those limits. (By the same token, a drug that has a particular expiration date rarely if ever becomes less effective or more toxic after the expiry date.) Finally, I'll point out that in some settings -- think resource poor areas like tropical Africa -- the accuracy of NAAT testing for STIs, as well as for many other pathogens, has been shown to be unaffected by very prolonged transit time or failed refrigeration, with temperatures in transit often >40C.