Table 3.
LOD comparison between the Roche Cobas Amplicor and Abbott RealTime CT/NG testsa
| Dilution | % detection (no. of equivocal or indeterminate results) |
|||||
|---|---|---|---|---|---|---|
|
C. trachomatis |
N. gonorrhoeae |
|||||
| Roche assay with M4-RT medium | Abbott assay with M4-RT medium | Abbott assay with ATB | Roche assay with M4-RT medium | Abbott assay with M4-RT medium | Abbott assay with ATB | |
| 1:100 | 100 (1) | ND | ND | 100 (1) | ND | ND |
| 1:500 | 70 (1) | 100 | 100 | 95 (13) | 100 | 100 |
| 1:2,000 | 25 | 65 | 60 | 30 (6) | 100 | 100 |
| 1:5,000 | 15 | 10 | 25 | 30 (6) | 90 | 100 |
a
Values represent percentages of 20 replicates tested by the Abbott and Roche methods that were positive at each dilution of the AmpliTrol CT/GC control material. Samples tested by the Abbott method were diluted in either M4-RT medium or Abbott transport buffer (ATB). The numbers of test results in the Roche equivocal range (C. trachomatis) or expanded indeterminate range (N. gonorrhoeae) are indicated in parentheses. Note that these results were scored as positive results for the calculation of the percentages presented in this table (see Materials and Methods for the rationale). ND, testing not done.