[Single-tube nested polymerase chain reaction technique in detecting Mycobacterium tuberculosis DNA].
OBJECTIVE
To study the sensitivity and specificity of single-tube nested polymerase chain reaction (SN-PCR) technique in detecting Mycobacterium tuberculosis DNA in paraffin-embedded tissues.


METHODS
BCG DNA and the paraffin-embedded tissues of 30 cases with typical tuberculous lymphadenitis were examined to detect the IS6110 specific insertion sequences DNA of Mycobacterium tuberculosis complex by general PCR(G-PCR), double-tube nested PCR (DN-PCR) and SN-PCR techniques.


RESULTS
Fifteen fg or more BCG DNA could show positive results by DN-PCR and SN-PCR techniques, while 480 fg by G-PCR method. The positive rates of G-PCR, DN-PCR, and SN-PCR in detecting Mycobacterium tuberculosis DNA in 30 cases with tuberculous lymphadenitis were 43%, 100%, and 100% respectively, all of which were significantly different (P < 0.01) from that of the acid-fast staining method (10%). Significant differences in the positive rates also existed between G-PCR and DN-PCR, G-PCR and SN-PCR (both P < 0.01), while the positive rates of DN-PCR and SN-PCR were found same.


CONCLUSIONS
The sensitivities of nested PCR techniques in detecting Mycobacterium tuberculosis are significantly higher than that of G-PCR, whereas the sensitivities as well as the specificities of SN-PCR and DN-PCR are the same. Thus SN-PCR seems more practicable.
Ma
H
H
Department of Pathology, Tianjin Medical University, Tianjin 300070.
Zhu
J
J
Zhang
N
N
D004269:DNA, Bacterial / Q000032:analysis*; D006801:Humans; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification*; D016133:Polymerase Chain Reaction / Q000379:methods; D014388:Tuberculosis, Lymph Node / Q000382:microbiology*
D004269:DNA, Bacterial