It is very difficult to predict why one lab has given positive results while other lab gave negative results. The discrepancy is based on many factors:
- Time of sample collection
- Method of sample collection
- Kits used by different labs
- QC procedure followed by the labs
- Cut-off values for CT used at labs
CT value of Diag is 37, according to the kits used in the lab and basis of intermachine comparison and repeatability studies. Having a higher CT value helps the detection of the lowest available viral load in a patient.