Quantification of mycobacterial proteins in extrapulmonary tuberculosis cases by nano-based real-time immuno-PCR

Diagnosis of extrapulmonary tuberculosis (EPTB) is difficult, and a rapid and dependable diagnostic test is urgently needed. A nano-based assay, SYBR Green magnetic bead-coupled gold nanoparticle-based real-time immuno-polymerase chain reaction (MB-AuNP-RT-I-PCR) was studied for the quantitative detection of MPT-64+CFP-10 proteins in clinically suspected EPTB patients. A wide range (270 fg/ml–9.9 ng/ml) of MPT-64+CFP-10 was quantified by MB-AuNP-RT-I-PCR in EPTB cases, whereas magneto-ELISA demonstrated a narrow range (1.8–10 ng/ml). Furthermore, high sensitivity (88.2%) and specificity (100%) were attained by MB-AuNP-RT-I-PCR in EPTB (n = 51) and non-TB control (n = 49) subjects, respectively. Both MB-AuNP-I-PCR/magneto-ELISA exhibited significantly lower (p