Objective: To carry out a quantitative traceability study on cystatin C, and to develop cystatin Cfrozen human serum national standard, which can be used for evaluating the accuracy of cystatin C test kits,and improving the ability of human serum cystatin C detection. Methods: Human serum samples were used asraw materials for aseptic sub-packaging and preparation of cystatin C frozen human serum national standard.The candidate of cystatin C frozen human serum national standard was assigned and calibrated by the method of multi-laboratory joint assignment, which was traceable to the international standard ERM-DA471/IFCC, and theaccuracy of the traceability chain has been verifi ed. The homogeneity and stability of the national standard wasverifi ed by the method of immune turbidimetry. Results: The cystatin C frozen human serum national standardwas established, which contains two concentration levels: level 1 (0.94 ± 0.03) mg·L^-1 (k=2), Level 2 (3.52 ± 0.09)mg·L^-1 (k=2); cystatin C frozen human serum national standard has good homogeneity and stability. The resultsof the 30-day short-term stability study showed that cystatin C frozen human serum national standard (level 1 andlevel 2) were stable for 5 days at room temperature; at 2-8 ℃, level 1 can be stable for 10 days and level 2 canbe stable for 20 days. At -20 ℃, both level 1 and level 2 can be stable for at least 30 days. The accuracy of thetraceability was verifi ed by using the serum reference panel and clinical serum samples, study results show that thenational standard and international standard ERM-DA471/IFCC have good traceability. Conclusion: The CystatinC frozen human serum national standard (360046-202001) has been approved and provided to the society withthe quantitative traceability study, which can be used for the accuracy evaluation of the cystatin C detection kit inhuman serum and the accuracy evaluation of clinical laboratory detection system values.

Objective: To explore potential problems in current reference materials development by selectingone representative with important clinical signifi cance for evaluation, and to discuss the optimization of producedpath according to the results to better improve the standardization of inspection reference system, based on thestatus of biochemical and immunological standard reference materials in the clinical reference system. Methods:According to the standards of EP14-A3 of the Clinical and Laboratory Standards Institute and WS/T 356-2011 of the National Center for Clinical Laboratories, the evaluation scheme was set up. 4 creatinine in frozen humanserum reference materials produced by reference methods from two diff erent domestic organizations and 21 freshhuman serum samples, were tested by reference methods of isotope dilution mass spectrometry and conventionalmethods of sarcosine oxidase according to the scheme. After processing the test results, the accuracy, matrixeff ects and commutability of the reference materials were studied. Results: The result of 4 reference materials and21 fresh human serum samples displayed diff erence in accuracy and matrix eff ect including reference methods andconventional methods. Three reference materials cannot ensure that the results within the range of target value ±uncertainty from reference methods, the deviation of GBW09170 and GBW09171 increased in the conventionalmethods, GBW09171 also showed matrix eff ects. Conclusion: Clinical applicability should be fully consideredin the development process of biochemical and immunological standard reference materials. When referencemethods are used to produce biochemical and immunological reference materials, such as creatinine in thisevaluation, attention should be paid to the diff erence of diff erent reference methods, and joint assignments shouldbe considered. At the same time, the commutability among diff erent methods should be fully considered to ensurethe accurate transfer of quantitative values as for optimization of produced path, supporting precision medicine.

Objective: To discuss the key requirements of quality control technology for colloidal goldimmunochromatography qualitative detection reagents, aiming to provide reference for quality control andevaluation of production enterprises and inspection institutions, and eff ectively promote the quality level of such invitro diagnostic reagents. Method: Based on the quality standard requirements and classifi cation management ofcolloidal gold immunochromatography qualitative detection reagents, analyze the key performance elements of thistype of reagent quality, put forward corresponding suggestions, improve reagent quality. Results and Conclusion:Quality control and evaluation are the core elements that run through the entire product process. Membrane width,liquid migration speed, negative compliance rate, positive compliance rate, detection limit and repeatability are thekey performance indicators for quality control and evaluation of colloidal gold immunochromatography qualitativedetection reagents, which are crucial for the quality of reagents. Relevant production and R&D enterprises shouldreasonably design performance requirements and improve quality management systems, inspection agenciesshould conduct quality evaluations based on the key product performance points, regulatory authorities shouldaccelerate the revision of standards and strengthen post listing supervision based on industry and regulatory needs.Control these key performance indicators from various aspects of production, inspection, and supervision to improve the quality standards of reagents, so as to meet the clinical and regulatory needs.

Objective: To evaluate performance of BCR-ABL fusion gene testing kit by digital PCR methodusing BCR-ABL quantitative standard. Methods: The RNA of standard was extracted and its concentration andpurity was determined. The different BCR-ABL fusion gene testing kits (digital PCR method) and the digitalPCR instrument were used for detection. The molecular response of BCR-ABL fusion gene was acquired forquantitative standard. Results: The MR absolute deviation of accuracy standards WS2 and WS3 did not exceed± 0.5 log. The detection limit standard WS4 could be detected positive mutation in the BCR-ABL fusion gene.The MR coeffi cient of variation (CV) of repeatability standards WS1 and WS4 was less than 3.0%. Conclusion:The performance indicators of accuracy, detection limit and repeatability of BCR-ABL fusion gene quantitativetesting kits (digital PCR method) can all meet the requirements of Industry Standards for Breakpoint Cluster Region-Abelson Leukemia Virus (BCR-ABL) Fusion Gene Testing Kits, providing technical support for theimplementation of the standard.

Objective: To systematically elucidate the principles of clinical trial design of the companiondiagnostic devices (CDx) in our country, and to provide references for the clinical trials of related CDx. Methods:Based on the diff erent development models of CDx, the clinical trial designs of the original and non-original CDxdeveloped simultaneously with anti-tumor drugs in China were introduced. Combined with the considerationsduring the relevant product technical review, the science and rationality of the clinical trials design of CDx wereanalyzed in depth. Results and Conclusion: The CDx plays a very important role in the clinical application of theanti-tumor drugs. The clinical trials of the CDx and the clinical trials of anti-tumor drugs are closely related. Thereare multiple types of designs for clinical trials of this kind of products. Clinical trial main investigators shouldchoose the appropriate clinical trial designs based on the specifi c conditions of product development mode andproduct detection markers, which could evaluate the clinical signifi cance of the product more scientifi cally andreasonably, and promote the product to market as soon as possible.