Comparison of Cross Priming Amplification and Loop Mediated Amplification for Tuberculosis Detection in an Integrated Diagnostic Device
Creecy, Amy Elizabeth
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2013-12-09
Abstract
Tuberculosis infects one out of three individuals worldwide. In order to control tuberculosis infection, accurate diagnostics are needed at the point-of-care. An ideal point-of-care diagnostic for tuberculosis would include an integrated system for lysis of the bacteria, extraction of the DNA from the bacterial lysate and the sputum, and detection of a specific biomarker. We compared the use of two different isothermal amplification methods, cross priming amplification (CPA) and loop mediated amplification (LAMP), for the detection of tuberculosis within a previously developed extraction cassette designed for low resource areas. Under ideal laboratory conditions, CPA and LAMP had a limit of detection of 500 copies and 50 copies respectively. As part of an integrated system, CPA and LAMP detected a concentration of bacteria at 1X103 cells/mL at 46 ± 5.8 minutes and 57 ± 4.6 minutes. For the integrated system of tuberculosis detection, CPA generates faster results. However, LAMP was shown to have a lower limit of detection and more specificity under ideal conditions. Overall, this study supports the continued investigation of using isothermal amplification methods combined with a low resource extraction cassette as a point-of-care diagnostic test.