TABLE 1.

Detection of C. pneumoniae DNA in a ready-to-use dilution series in four laboratories

SampleAmt of chlamydiae/PCR mixtureaPCR resultb by laboratory
No. of IFUNo. of EBscAmt of DNAABCD
S1301,0001.3 ng++++
S2000
S33100130 pg++++
S4000
S50.31013 pg++++
S6000
S70.0311.3 pg++
S8000
S90.0030.1130 fg
S100.00030.0113 fg
  • a Amount of chlamydiae (IFU corresponding to elementary bodies or DNA) in a 10-μl amplified DNA extract/50 μl of first-round PCR mixture.

  • b +, reported as C. pneumoniae positive by nested PCR; −, reported as C. pneumoniae negative by nested PCR.

  • c EBs, elementary bodies.