Preparation of DTS panels for stability evaluation
The dilutions of the positive sera were carried out with negative sera. Serial dilutions were used to dilute positive sera to produce 4 levels of positive samples ranging from strong positive to weak positive, which was diluted 1:4. The negative serum samples were similarly prepared for DTS. Sufficient quantity of DTS panels were prepared for 15 weeks stability evaluation (based on the weekly testing), In addition, about 20% extra samples were prepared for any unexpected concern. All samples were stored at room temperature during the period of stability evaluation.