TABLE 1.
GC antigen detection in M. tuberculosis culture supernatanta
| Sample | Antigen concn (μg/ml)
|
|||
|---|---|---|---|---|
| Strain | Growth medium | Day 11 | Day 20 | Day 25 |
| Erdman | 7H9 | <10 | 103 ± 1 | ≥1,000b |
| Erdman | 7H9-T | <10 | 84 ± 8 | 252 ± 4 |
| CDC 1551 | 7H9 | <10 | ≥100 | ≥1,000 |
| CDC 1551 | 7H9-T | <10 | 91 ± 9 | 1,000 ± 100 |
a
Detection of GC antigen in the GC capture ELISA is indicated by the mean measured concentration of antigen ± standard deviation based on two separate measurements.
b
In some instances, the ELISA readout exhibited a prozone but did not taper, limiting the precison of the quantitation, and the concentration is expressed as ≥100 or ≥1,000 μg/ml (the minimum concentration of antigen detected).