Probit^{a} | C. pneumoniaeconcn (IFU/ml)^{b} | No. of replicates needed to achieve sensitivity of^{c}: | |||
---|---|---|---|---|---|

50% | 80% | 90% | 95% | ||

0.01 | 0.01 | 69 | 161 | 230 | 299 |

0.05 | 0.03 | 14 | 32 | 45 | 59 |

0.10 | 0.05 | 7 | 16 | 22 | 29 |

0.20 | 0.09 | 4 | 8 | 11 | 14 |

0.30 | 0.15 | 2 | 5 | 7 | 9 |

0.40 | 0.24 | 2 | 4 | 5 | 6 |

0.50 | 0.35 | 1 | 3 | 4 | 5 |

0.60 | 0.53 | 1 | 2 | 3 | 4 |

0.70 | 0.81 | 1 | 2 | 2 | 3 |

0.80 | 1.34 | 1 | 1 | 2 | 2 |

0.90 | 2.70 | 1 | 1 | 1 | 2 |

0.95 | 4.79 | 1 | 1 | 1 | 1 |

0.99 | 14.10 | 1 | 1 | 1 | 1 |

↵a Probit, predicted proportion of replicates positive from probit regression analysis (SPSS), based on 10 replicates of 16 dilutions of

*C. pneumoniae*ATCC VR-1310 (see the text).↵b

*C. pneumoniae*ATCC VR-1310 concentration as calculated from probit analysis.↵c Replicates calculated in Microsoft Excel spreadsheet from the following equation: probability (at least 1 positive in

*n*replicates) = 1 − (1 − probit)^{n}.