ABSTRACT
【Objective】 To verify the key performance parameters of Roche Cobas S201 multiplex NAT for blood donors, so as to provide data for the conformation of multiplex NAT performance and establish a scientific and feasible verification scheme. 【Methods】 Comprehensive performance verification on four key parameters of ROCHE COBAS S201 multiplex NAT system, including the 95% detection limit, compliance rate, anti-interference ability and operator comparison were conducted. The data were compared with the specifications provided by the manufacturer to evaluate the performance of laboratory testing system and ensure the quality of blood testing. 【Results】 2 sets of COBAS S201 multiplex NAT system in our laboratory were used to perform 5 times of the 95% detection limit value declared by the manufacturer for individual tests. The experimental results showed that the target NAT can be detected 100% and the lower limit of determination was verified. Single-virus NAT was performed to detect 5 different HBV DNA concentrations (25 ~400 IU/mL), 5 different HCV RNA concentrations (25 ~400 IU/mL), 5 different HIV RNA Concentration (100~1 000 IU/mL), and 5 negative tubes. The experimental results showed that all detected values of 20 tubes were 100% consistent with the true value, and the performance parameter "coincidence rate" was verified. Samples containing lipoemia, hemolysis, with ALT>50 mL/L and syphilis-positive endogenous interfering substances with 3 times of the 95% detection limit value were tested for 3 times, and results showed both response rate (3/3) and yielding rate reached 100%. In the control group (with none or in the normal range of interfering substances), reactivity was detected in samples with extremely low concentration of 3 times of the 95% detection limit, showing no significant difference (P>0.05). Above results fully showed that the existence of interference substances (lipidemia, hemolysis, ALT ≥ 50 and syphilis positive) in the blood of donors had no significant effect on the yielding of HBV/HCV/HIV virus target nucleic acids. Different operators performed the sample loading tests with same instrument, reagent and specimen showed 100% consistency in the results. It could be preliminarily assessed that there was no difference in the operations between the operators in this verification. 【Conclusion】 The verification scheme of the multiplex NAT system for methodology performance index (95% detection limit, coincidence rate, anti-interference ability, and operator comparison) established in this study, showed simple, flexible, scientific and feasible characteristics and could provide reference and data support for domestic blood transfusion services in acid detection.
ABSTRACT
Objective To modify the purified water analysis methods in the Chinese Pharmacopoeia (Vol .Ⅱ ,Edition 2010) ,and mainly focus on the pH value determination ,analysis of nitrate and nitrite ,and the inspection of microorganism . Methods The usage of regents and colorimetric tubes in the analysis of nitrate and nitrite were inquired ,the feasibility of plat-ing culture used in the inspection of microorganism were proposed ,and the suggestion of using more instrumental analysis in-stead of titrimetric analysis in the purified water inspection wasraised .Results The choice of colormetric apparatus and the precision of the regents were explicit .The plating method was better in convenience and reliability than membrane-filter proce-dure during the microorganism inspection .Instrumental analysis is the trend of purified water inspection and deserved to be rec-ommended .Conclusion Based on our own and others′studies ,the methods of impurity analysis are improved ,which might be accepted in the revision of Chinese Pharmacopoeia in future .