Nested amplification protocol for the detection of Mycobacterium tuberculosis

Several methods for rapid diagnosis of tuberculosis have been devised through DNA amplification. However, the chemically strong cell wall of the species, the presumptively low numbers of organisms and their uneven distribution in clinical samples, and the lack of a "gold standard" for diagnosing tuberculosis, have hindered the routine clinical use of this method. In a pediatric patient group, these factors are more perplexing. To circumvent these problems, we made use of nested amplification and developed a standard protocol for extracting DNA from various forms of clinical samples which were suitable to our clinical laboratory. It is our impression that the overall sensitivity, including technical bias accompanying this method, is equal to, or at least greater than, that of culture. Most notably, the rapidity in obtaining results and the simplicity in handling, storage and transfer of samples are the principal advantages of this method.