Objective To study the quality control of urinary arsenic detection .Methods Quality control before ,during and after analysis were performed to avoid the random error and control the system errors .Results The low detection value of self-made quality control material of urinary arsenic and coefficient of variation (CV) were (0 .644 ± 0 .024) mg/L and 3 .72% ,respectively , while the high detection value and CV were (1 .353 ± 0 .042) mg/L and 3 .14% ,respectively .Conclusion Quality control before , during and after analysis may effectively reduce the incidence of random error and control the system error of urinary arsenic detec-tion and ensure the accuracy of test results .

AIM: To investigate the differential expression profile between nasopharyngeal carcinoma cell line CNE1 and its steady EBV-LMP1-transfected cell line CNE1-LMP1, and to explore the regulatory effect of LMP1 on oncomiRs expression in CNE1 cell line. METHODS: A microRNA array that targets 132 of the most well studied oncomiRs was used to detect the expression profile of CNE1 and CNE1-LMP1. qRT-PCR assay were used to verify the expression data detected by microarray. RESULTS: Among the restricted 132 miRNAs, 30 were detectable. Among which, 30 were expressed in CNE1-LMP1, 19 in CNE1 and 11 were specifically expressed in CNE1-LMP1. Among the 19 shared miRNAs, the expression level of 6 miRNAs (hsa-miR-19b, hsa-miR-17-3p, hsa-miR-22, hsa-miR-149, hsa-miR-150 and hsa-miR-188) elevated over two folds in CNE1-LMP1. No decrease in miRNA expression more than two folds was observed. qRT-PCR confirmed the expression difference of these six miRNAs (P<0.01). Among the 11 specifically expressed miRNAs in CNE1-LMP1, hsa-miR-122a showed the highest expression level surpassing the internal control sample. CONCLUSION: Our data suggest that LMP1 may play an important role in regulating the expression of miRNAs in tumor, which may be another important pathway employed by LMP1 in the development of nasopharyngeal carcinoma.

ed to construct a series of positive control materials that are applicable to many other immunoassays.