Glycated hemoglobin plays an important role in diabetes management.International standardization of HbA1c initiated 20 years ago and has been performed successfully.The standardization of HbA1c in China has been started several years 3 labs have become approved laboratories of IFCC reference network.Reference methods were applied to transfer trueness in the national trueness verification project.The measurement performance of HbA1c testing have improved in recent years and the between-lab CVs reduced evidently.All participants will continue efforts to improve HbA1c testing to fulfill the clinical needs.

Objective To investigate the stability of glycated hemoglobin HbA1c in whole blood sample measured by Tosoh G7, Roche/Hitachi 7170A and NycoCard READER Ⅱ under different storage conditions. Methods Three whole blood samples (EDTA anticoagulated) with different glycated hemoglobin levels and one whole blood sample (heparin anticoagulated) were collected and stored at -80 ℃, -20 ℃, 4 ℃,room temperature(15 -25 ℃), and 37 ℃ HbA1c was analyzed by each method on days 1, 2, 5, 7, 9, 14, 21,28, 35, 42, 49, 56, 63 and 70 respectively. Results The results of sample stored at -80 ℃ appear to be stable for Tesoh G7 and Roche/Hitachi 7170A method. The coefficients of variation (CV) for Tosoh G7 was 0.54%-1.22%. The CV for Roche/Hitachi 7170A was 0.86% -1.82%. When samples was detected with Tosoh G7 method, the results was consistent when the sample was stored at -20 ℃ for 14 days, 4 ℃ for 63 days, room temperature for 5 days, and 37 ℃ for less than 1 day. When samples was detected with Roche/Hitachi 7170A method, the results was consistent when the samples was stored at -20 ℃ for 21 days, 4 ℃ for 42 days, room temperature for 7 days, and 37 ℃ for less than 1 day. The NycoCard READER Ⅱ showed stability at 4 ℃ for 9 days, and room temperature for less than 1 days. Conclusions The stability of whole blood samples is dependent on different methods. Storage time under different temperatures is different.

Isotope dilution mass spectrometry is a reliable principle for small molecule analyte measurements.It is a precise,accurate method with very high specificity,which is very suitable for lowconcentration steroid hormones tests.The published reference methods are all based on this principle so far.In this paper,the applications of isotope dilution mass spectrometry in the determination of steroid hormones were reviewed.

Objective To investigate the results of different measuring procedures of hemoglobin A1c (HbA1c) trueness verification scheme in China.Methods Cross sectional survey.The data were collected via the External Quality Assessment (EQA) software from laboratories participated in the First HbA1c trueness verification EQA.Then the collected data were divided into several groups based on laboratory instruments and the data from less than 5 group were excluded.The observed imprecision, bias and sigma (σ) were calculated and the bias％ and CV％ were drew in the sigma chart.The average bias％, CV％ and weighted average σ of each level were also calculated.Results Total 123 laboratories were divided into 9 groups and setting 6％ as the Allowable Total Error, the average bias％, CV％ and weighted average σ of 201411 (target value was 5.4％) were 3.70％, 4.55％ and 0.51 respectively σ, of 201412 (target value was 7.8％)were 2.42％ , 3.56％ and 1.24σ respectively.None of the group achieved the 2σ quality of 201411, and 1 group achieved the 2σ quality of 201412.Conclusions There are obvious biases among the results of many measuring systems and the target value assigned by reference measuring procedures of HbA1c, as well as the imprecision.The Sigma External Quality Assessment Chart is a visual tool, indicating that the quality of measuring systems necessitate improvement therefore to ensure the reliability of results and make better use of HbA1c in clinical application.

Objective To investigate preanalytical and intraindividual biological variations of 19 biochemistry analytes. Methods For the study of preanalytical variations, 10 consecutive blood specimens were taken from each of 21 individuals and the specimens were taken from different arms and with various evacuated blood tubes and venous occlusion durations and processed with different storages before and after centrifugal separation of serum. Another 3 aliquots of blood, each at an interval of 1 week, were taken from the individuals for the study of intraindividual biological variations. All the serum samples were analyzed in duplicate for 19 biochemistry analytes. Analysis of variance was performed on the results for the estimation of preanalytical and biological variations. Results Various preanalytical treatments or factors caused some systematic variations but random specimen errors were the main contributors of preanalytical variations. Chloride, sodium and calcium showed preanalytical variations of less than 1% and other analytes ranging from 1%-7%. Different analytes showed varied intraindividual biological variations. The least biological variations ( <2% ) were observed on chloride, sodium and calcium and the largest ( >20% ) on bilirubin,triglycerides, alanine aminotransferase and creafine kinase. Conclusions Preanalytical variations under laboratory settings in China and intraindividual biological variations in Chinese for 19 biochemistry analytes have been estimated. These data will be useful in the estimation of measurement uncertainty and the interpretation of clinical laboratory results.

Objective To research on a whole blood control material for lymphocyte subset counting by flow cytometry(FCM).Methods To detect lymphocyte subset in whole blood with different preservers by flow cytometric multi-color analysis.Results whole blood control material for lymphocyte subset counting by FCM was prepared.In 2-8℃ refrigerator, the light scatter and CD45 of leukocytes of whole blood control were stable in 72 days. The cluster of lymphocyte, monocyte, neutrophil in plot were separated easily from debris. The lymphocyte subset of whole blood control can be counted by FSC/SSC or CD45/SSC gating. The variation of lymphocyte subset count was less in different preserving day. The coefficient of variation (CV) of lymphocyte subset count was less than 6.5% in our laboratory and less than 13% in external quality assessment among 56 laboratories in China.Conclusion The whole blood control prepared by us can be used for internal quality control and external quality assessment in lymphocyte subset counting by FCM, it is very important signification to ensure the quality and accuracy of lymphocyte subset count.

This article summarized recent correlative literatures focusing on international standards on glycated hemoglobin.The basic concept,determination of glycated hemoglobin,the present review in laboratory measurement and metrological traceability was introduced.The international community has established reference system and metrological traceability to the International System of Units on HbA1c.Determination in glycated hemoglobin is still in incipient stage in our country.Both clinical laboratorians awareness and clinical determination need to be strengthened.

Objective To evaluate the analytical performance of lipid testing with six sigma(a) in order to promote the quality improvement.Methods Sixty-four Laboratories participated in trueness verification program and Internet-Based Interlaboratory Comparison of Internal Quality Control Data program lipid testing in 2012 were included in this study.The CVs and Bias of TC,TG,HDL-C,and LDL-C for each laboratory were evaluated from the reporting data.The sigma metrics based on the Tea from National Cholesterol Education Program according to the formula:σ =(TEa-Bias)/CV for each analyte.Quality goal index (QGI) was also calculated to investigate the reason for dissatisfied performance as follows:QGI =Bias/ (1.5CV).Results The rates for σ≥6 of TC,TG,HDL-C,and LDL-C were 21.9％,34.4％,9.38％,and 18.8％,respectively.The corresponding rates for 3 ≤ σ ＜ 6 were 31.3％,29.7％,29.7％,and 34.4％,while the rates for σ ＜ 3 were 46.9％,35.9％,60.9％,and 46.9％,severally.For analytes which σ were less than 3,91.3％-100％ of the laboratories should improve the trueness first,0.00％-8.75％ of the laboratories should improve the precision,and 0.00％-2.08％ should improve both.Conclusions Six sigma is an effective tool for quality control in clinical laboratory,which can help improve the quality level for laboratory testing.The analysis of performance of the lipid testing shows that further effort is acquired to enhance the supervision of the trueness verification.

Objective To investigate and analyze the reasons of fa0ilure in external quality assessment(EQA) for routine chemistry and provide the basis for the corrective and preventive actions.Methods Based on the network system of NCCL EQA the reasons of failure in 2013 national routine chemistry external quality assessment program were investigated,among which the reasons were classified and analyzed with seven sources of problems which were clerical errors,methodological problems,equipment problems,technical problems,EQA materials problems,EQA Evaluation problems and unable to explain after investigation.Results The return rate of this root cause investigation for each analyte ranged from 33.3％ to 80.0％.The major reason for unacceptable analyte included clerical errors (6.5％) (decimal point position error:70.1％;unit error:20.8％;instrument or method coding error:8.1％),methodological problems (45.1％)(calibration:54.2％;reagent:38.0％;EQA material:7.8％),equipment problems (28.5％) (no regular maintenance:98.0％;pipeline error:2.0％),technical problems (8.2％) (do not follow SOP:80.4％;EQA material redissolve error:10.6％;placing order error:9.0％) and unable to explain (11.7％) (system error:68.2％;random error:31.8％).There were no EQA materials problems or EQA Evaluation problems in this survey.Analysis systems' grouping statistics were implemented for seven analytes including sodium,chlorine,phosphorus,direct bilirubin,total iron binding capacity,copper,and zinc.Unsatisfied EQA proportions of mating system were lower than nonmatching ones for the majority of analytes.Conclutions Further work on EQA should be undertaken by clinical laboratories.Laboratories should use reagents with high quality as well as improve the operation technology and sense of responsibility.Only in this way,can the accuracy and reliability of testing results be guaranteed.