RESUMEN
【Objective】 To analyze the difference of the internal control (IC) Ct value of two sets of blood nucleic acid detection(NAT) systems for individual donation and explore the feasibility of the IC Ct value used as stability evaluation index of NAT system. 【Methods】 A total of 4342 blood samples were randomly selected from our center from June to November 2020, and the IC Ct values of NAT system were classified into three categories: 1) classified by detection items: HBV, HCV and HIV; 2) classified by sample type: negative control (NC), positive control (PC), internal quality control (QC), blood donor sample (S); 3) classified by different instruments: system A and system B, and the differences of IC Ct value were analyzed and compared. 【Results】 A total of 14 196 IC Ct values of NAT were collected, showing a non-normal distribution. 1) classified by detection items: there were differences in the median of overall IC Ct values of HBV, HCV and HIV (H=859.6, P0.05), except for HBV QC (Z=1 635)and S (Z=1 848 560), HCV S (Z=1 957 844), HIV S (Z= 2 217 855) (P<0.01). No difference in IC values (P<0.01) was noted for any detection items (NC, PC, QC and S) in the same set of detection system. 【Conclusion】 Although IC values trended to be different due to types of sample, the NC, PC, and QC samples that come with the original reagents were identical in the two detection systems. The change of IC Ct value may be used as an evaluation index for the stability of the detection system.