The APTIMA transcription-mediated amplification assays for Chlamydia trachomatis and Neisseria gonorrhoeae have the greatest sensitivity of all the commercial nucleic acid amplification tests for the diagnosis of infections from noninvasive samples that may contain small amounts of nucleic acid. They have received extensive attention in male and female populations of varying prevalences of infection. Vulvovaginal swabs appear to be the specimen of choice (either self-collected or physician collected) in women and first-catch urine in men. Gen-Probe Inc. has created alternate amplification primers for confirmatory or initial single organism testing. With automation of the TIGRIS instrument, the assays should prove to be useful in high-volume laboratories.