Analysis of the results of the nationwide interlaboratory comparison of gross α and gross β radioactivity measurement / 中国辐射卫生

Objective To summarize and improve the related technical issues by analyzing the nationwide interlaboratory comparison of gross α and gross β radioactivity measurement over the years. Methods According to the requirements of interlaboratory comparison and the national standards, the gross α and gross β radioactivity in water were measured, and the results were analyzed to identify the influencing factors. Results From 2018 to 2022, our laboratory participated in five nationwide interlaboratory comparisons of gross α and gross β radioactivity measurement. The Z-test values for gross α and gross β measurement ranged from −0.24 to 1.8 and −1.4 to 0.35, respectively. The relative deviations ranged from −4% to 32% and −18% to 6%, respectively. All comparisons were within the acceptable ranges. Conclusion The analysis of comparisons showed that the results were within the acceptable ranges. The relative deviations between the measurement and the reference values have decreased over the years. The summary and improvement of related technologies have improved the measurement accuracy.

An interlaboratory comparison study on the detection of RUNX1-RUNX1T1 fusion transcript levels and WT1 transcript levels / 中华血液学杂志

Objective@#To investigate the current status and real performance of the detection of RUNX1-RUNX1T1 fusion transcript levels and WT1 transcript levels in China through interlaboratory comparison.@*Methods@#Peking University People’s Hospital (PKUPH) prepared the samples for comparison. That is, the fresh RUNX1-RUNX1T1 positive (+) bone morrow nucleated cells were serially diluted with RUNX1-RUNX1T1 negative (-) nucleated cells from different patients. Totally 23 sets with 14 different samples per set were prepared. TRIzol reagent was added in each tube and thoroughly mixed with cells for homogenization. Each laboratory simultaneously tested RUNX1-RUNX1T1 and WT1 transcript levels of one set of samples by real-time quantitative PCR method. All transcript levels were reported as the percentage of RUNX1-RUNX1T1 or WT1 transcript copies/ABL copies. Spearman correlation coefficient between the reported transcript levels of each participated laboratory and those of PKUPH was calculated.@*Results@#①RUNX1-RUNX1T1 comparison: 9 samples were (+) and 5 were (-) , the false negative and positive rates of the 20 participated laboratories were 0 (0/180) and 5% (5/100) , respectively. The reported transcript levels of all 9 positive samples were different among laboratories. The median reported transcript levels of 9 positive samples were from 0.060% to 176.7%, which covered 3.5-log. The ratios of each sample’s highest to the lowest reported transcript levels were from 5.5 to 12.3 (one result which obviously deviated from other laboratories’ results was not included) , 85% (17/20) of the laboratories had correlation coefficient ≥0.98. ②WT1 comparison: The median reported transcript levels of all 14 samples were from 0.17% to 67.6%, which covered 2.6-log. The ratios of each sample’s highest to the lowest reported transcript levels were from 5.3-13.7, 62% (13/21) of the laboratories had correlation coefficient ≥0.98. ③ The relative relationship of the reported RUNX1-RUNX1T1 transcript levels between the participants and PKUPH was not always consistent with that of WT1 transcript levels. Both RUNX1-RUNX1T1 and WT1 transcript levels from 2 and 7 laboratories were individually lower than and higher than those of PKUPH, whereas for the rest 11 laboratories, one transcript level was higher than and the other was lower than that of PKUPH.@*Conclusion@#The reported RUNX1-RUNX1T1 and WT1 transcript levels were different among laboratories for the same sample. Most of the participated laboratories reported highly consistent result with that of PKUPH. The relationship between laboratories of the different transcript levels may not be the same.

An interlaboratory comparison study on the detection of RUNX1-RUNX1T1 fusion transcript levels and WT1 transcript levels / 中华血液学杂志

Objective: To investigate the current status and real performance of the detection of RUNX1-RUNX1T1 fusion transcript levels and WT1 transcript levels in China through interlaboratory comparison. Methods: Peking University People's Hospital (PKUPH) prepared the samples for comparison. That is, the fresh RUNX1-RUNX1T1 positive (+) bone morrow nucleated cells were serially diluted with RUNX1-RUNX1T1 negative (-) nucleated cells from different patients. Totally 23 sets with 14 different samples per set were prepared. TRIzol reagent was added in each tube and thoroughly mixed with cells for homogenization. Each laboratory simultaneously tested RUNX1-RUNX1T1 and WT1 transcript levels of one set of samples by real-time quantitative PCR method. All transcript levels were reported as the percentage of RUNX1-RUNX1T1 or WT1 transcript copies/ABL copies. Spearman correlation coefficient between the reported transcript levels of each participated laboratory and those of PKUPH was calculated. Results: ①RUNX1-RUNX1T1 comparison: 9 samples were (+) and 5 were (-) , the false negative and positive rates of the 20 participated laboratories were 0 (0/180) and 5% (5/100) , respectively. The reported transcript levels of all 9 positive samples were different among laboratories. The median reported transcript levels of 9 positive samples were from 0.060% to 176.7%, which covered 3.5-log. The ratios of each sample's highest to the lowest reported transcript levels were from 5.5 to 12.3 (one result which obviously deviated from other laboratories' results was not included) , 85% (17/20) of the laboratories had correlation coefficient ≥0.98. ②WT1 comparison: The median reported transcript levels of all 14 samples were from 0.17% to 67.6%, which covered 2.6-log. The ratios of each sample's highest to the lowest reported transcript levels were from 5.3-13.7, 62% (13/21) of the laboratories had correlation coefficient ≥0.98. ③ The relative relationship of the reported RUNX1-RUNX1T1 transcript levels between the participants and PKUPH was not always consistent with that of WT1 transcript levels. Both RUNX1-RUNX1T1 and WT1 transcript levels from 2 and 7 laboratories were individually lower than and higher than those of PKUPH, whereas for the rest 11 laboratories, one transcript level was higher than and the other was lower than that of PKUPH. Conclusion: The reported RUNX1-RUNX1T1 and WT1 transcript levels were different among laboratories for the same sample. Most of the participated laboratories reported highly consistent result with that of PKUPH. The relationship between laboratories of the different transcript levels may not be the same.

Development of proficiency testing amples of chloroform and carbon tetrachloride activated carbon tubes and their application in inter-laboratory comparison tests / 中国职业医学

OBJECTIVE: To develop proficiency testing samples of chloroform and carbon tetrachloride in activated carbon tubes and analyze their application in inter-laboratory comparison tests in occupational health technical service organizations. METHODS: Three types of mass concentration proficiency testing samples of chloroform and carbon tetrachloride in activated carbon tubes were developed. Their homogeneity and stability were evaluated and the values were determined. The qualified samples were used for inter-laboratory comparison test in occupational health technical service organizations in the country. RESULTS: The prepared chloroform and carbon tetrachloride activated carbon tubes demonstrated good sample homogeneity. There was no significant difference in the measured values of the samples stored at room temperature for one year and the values measured on the day of preparation( P > 0. 05),and the stability was good.Among the 197 institutions participated in the inter-laboratory comparison test of chloroform,the satisfactory result accounted for 86. 29%( 170/197),the problematic results 7. 11%( 14/197),and the unsatisfactory results 6. 60%( 13/197). Among the 195 agencies that participated in the inter-laboratory comparison test of carbon tetrachloride,the satisfactory results accounted for 89. 74%( 175/195),the problematic results 3. 59%( 7/195),and the unsatisfactory results 6. 67%( 13/195). CONCLUSION: The homogenous and stable proficiency testing samples were successfully produced and can be used for inter-laboratory comparison test in occupational health technical service organizations.