Table 3.

LLODs of individual and multiplex real-time PCR assays

Assay and genomic equivalentMean CT (95% CIa)
B. pertussis IS481B. holmesii IS481B. holmesii IS1001-likeB. parapertussis IS1001ptxS1b
Individual RT-PCRs
    1,00022.3 (18.0-26.9)24.6 (18.9-30.2)24.6 (19.3-29.9)25.5 (22.8-28.1)30.1 (29.9-30.2)
    10026.0 (21.1-31.0)28.1 (21.9-34.3)28.1 (22.0-34.1)28.8 (25.8-31.8)33.4 (33.1-33.6)
    1029.4 (24.9-33.9)31.7 (25.5-37.9)31.4 (25.7-37.0)32.2 (29.3-35.2)37.1 (36.9-37.4)
    133.0 (28.2-37.9)34.8 (30.3-39.3)34.9 (28.8-41.0)35.8 (32.6-39.1)38.9 (38.5-39.4)c
    0.135.9 (33.4-38.4)36.7 (34.8-38.6)37.0 (34.4-39.5)37.5 (35.5-39.5)NDd
    0.0138.0 (35.8-40.3)ND38.5 (37.4-39.6)NDND
    0.001NDNDNDNDND
Multiplex RT-PCR
    1,00022.4 (18.0-26.9)25.1 (19.0-31.1)24.4 (19.1-29.6)25.8 (20.8-30.8)
    10026.1 (21.3-30.9)28.6 (22.3-35.0)27.8 (22.0-33.6)29.3 (24.4-34.2)
    1029.5 (25.0-34.0)32.1 (26.3-38.0)31.1 (25.9-36.3)32.9 (27.8-38.0)
    133.3 (28.5-38.1)35.8 (30.4-41.1)34.8 (28.3-41.2)35.9 (30.8-40.9)
    0.136.5 (33.3-39.7)37.6 (35.3-40.0)36.5 (33.6-39.4)38.7 (35.6-41.8)
    0.0137.4 (36.1-38.8)ND37.9 (32.3-43.6)ND
    0.001NDNDNDND
  • a CI, confidence interval.

  • b ptxS1 probe has Black Hole Quencher 1 on the position 14 T (underlined) (Table 1).

  • c Seventeen of 32 tests gave CT values generating this mean.

  • d ND, not detected.