NAAT testing can include a wide variety of testing methods. Some of the methods may include PCR (Polymerase Chain Reaction), LCR (Ligase Chain Reaction), SDA (Strand Displacement Technolody), or TMA (Transcription Mediated Amplification). These are the most common NAAT's used in laboratories today. The NAAT technology (i.e., PCR, LCR, SDA) isolates the bacterial DNA of chlamydia and gonorrhea, then uses a detailed heating and cooling process that amplifies the DNA. Once the DNA is amplified it is much easier to detect. Some sources state that the NAAT's have replaced the culture as the "gold standard" in testing for chlamydia and gonorrhea infection. Some of the reasons for this may be that the NAAT's are more sensitive, non-invasive (performed on urine specimen), and easier to transport than other testing technologies. These methods are sensitive enough to detect 1-10 bacteria because of their ability to amplify the target nucleic acid during the test procedure.