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A novel polymerase-based electrochemiluminescence DNA sensor was constructed for messenger RNA (mRNA) detection by cyclic chain displacement polymerization,assisted by target mRNA cycle,and quantum dots signal amplification.Firstly,the mercapto-modified capture-type capture DNA (CP) was immobilized on the surface of a magneto-controlled glassy carbon electrode via Au-S bond.After adding the target mRNA,CP was opened and hybridized with mRNA to form dsDNA.After adding polymerase,primer chain (DNA1) and the base,the primer chain was extended to replace the target mRNA.After one cycle,the mRNA chain could open another hairpin in order to carry out next cycle of amplification.Finally,electrochemical luminescence detection was carried out by adding DNA2 labeled TGA-CdTe quantum dots.The amplification of the target mRNA by the addition of polymerase and the signal combined with the quantum dot mark improved the sensitivity of the sensor greatly.The result showed that the logarithm of target mRNA concentration had a good linear relationship with the corresponding ECL signal in the range of 1 × 10-15-1 × 10-11mol/L,with the detection limit of 3.4 × 10-16mol/L(S/N=3).Under the optimal conditions,the recoveries of mRNA spiked in human serum sample were 97.2% -102.3%.This sensor exhibited good selectivity,stability and reproducibility.
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Objective To evaluate the comparability of the test results of two immunoassay systems based on the electrochemical luminescence and the fluorescence lateral flow immunoassay for serum procalcitonin (PCT).Methods Roche cobas system was used as the reference system,and fluorescence lateral flow immunoassay system of Shanghai Upper biotech company was used as evaluated system.A total of 141 clinical samples during November,2015 were detected by the two systems to obtain the correlation coefficient and the Kappa values at the two cutoff values(0.5,2.0 ng/ml).Results The two systems showed high correlation (Y=1.008X-0.032,r=0.995,P＜0.001) and low deviation (t=-0.230,P=0.819＞0.05) without statistic significance between two methods.Kappa values were 0.944,0.943 respectively at the two cutoff values (0.5,2.0 ng/ml).Conclusion The test results showed no significant difference between the two immunoassay systems,suggesting a consistency between them for clinical detection of PCT.All the observed indicators reached the clinical diagnostic requirements and the method of quantitative detection of PCT by fluorescence lateral flow immunoassya can be applied for the quick detection of clinical human PCT.
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Objective To explore the clinical significance of combined detection of carbohydrate antigen(CA)125,CA153,carcinoembryonic antigen(CEA) and tumor specific growth factor(TSGF) in diagnosis for breast cancer.Methods A total of 125 patients with breast cancer were recruited as objects in this study from march 2015 to march 2016,65 patients in breast cancer group,60 patients in benign breast disease group,meanwhile 55 healthy person were enrolled in the control group.Serum tumor markers such as CA125,CA153,CEA and TSGF were detected and compared in the three groups.Results The serum CA125,CA153,CEA and TSGF levels in the breast cancer group were significant higher than those of benign breast disease group and healthy group,the differences were statistical significant(P<0.05).At the same time,the sensitivity and specificity of joint detection of four kinds of serum tumor marker were 90.2% and 88.9%,which were higher than those of single serum tumor marker detection(χ2=26.12,P<0.05).Conclusion The four kinds of serum tumor markers combined testing not only increases the sensitivity of breast cancer diagnosis,but also improved the specificity of diagnosis of breast cancer.
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Objective To compare the analytical performance and results correlation of cortisol detection by the Beckman Access 2 Immunoassay System chemiluminescence system and the Roche COBAS E 411 electrochemical luminescence system .Methods The precision ,functional sensitivity ,reference range ,positive coincidence rate and negative coincidence rate of both Beckman Access 2 Immunoassay System and Roche COBAS E 411 systems for detecting cortisol were evaluated according to the method of ISO15198 .Results Both Beckman Access 2 Immunoassay System and Roche COBAS E 411 system exhibited better precision ,the functional sensitivity conformed to the lower limit of clinical detection set by the manufacturers ,after establishing the reference range of cortisol by the laboratory ,the cortisol values detected by these two systems were performed the linear regression analysis , the results indicated that the correlation between them was good ,the linear regression coefficient r2 =0 .977 ,and the positive and negative coincidence rates were 100% .Conclusion The two analytical systems have excellent performance for cortisol ,which all meet the clinical detection requirements .The methodological comparison shows good correlation between them ,and the detection re‐sults could be cited between these two systems by the regression equation .
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Objective:To detect anaemia parameter methodology performance for validation of Roche Cobas E601 automatic electrochemical luminescence immunity analyzer.Methods:Recommended by the American association of clinical laboratory standardization (CLSI) method was developed for the determination of folic acid, iron, protein, and this precision, accuracy, linear range, sensitivity, biological reference range and carry pollution index, and validated.Results: Cohas E601 determination of folic acid, iron, protein and precision, the daytime in this batch variation coefficient were 3.03%~4.27% and 3.51%~4.68%. Relative bias must lean on(%) between -3.54%~4.46%. The scope of determination of linear range and the manufacturer to provide similar. Folic acid, iron, protein and numerical value with the determination of this instrument manufacturers provide reference interval coincidence rate were 90.0%, 85.0% and 90.0% respectivel. Instrument to detect carry pollution rate is 0.04%~0.16%. CohasE601 detection sensitivity were 0.23 ng/ml, 0.21 ng/ml and 0.19 pg/ml.Conclusion: Cobas E601 detect folic acid, iron, protein and good performance of this methodology, but manufacturers provide biological reference range is not suitable for the local crowd, should establish the corresponding normal reference range.
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Objective To evaluate the performance verification of AFP and CEA detected by Roche Cobas 6000 automatic electrochemical luminescence analyzer.Methods Serum samples in hospital patients during April 1 to 4,2014 were collected and mixed.Samples with the different levels of AFP and CEA were prepared.Referring to CLSI EP files and other docu-ments,the precision,accuracy and the reported linear range of AFP and CEA from Roche Cobas 6000 automatic electrochem-ical luminescence analyzer were verified.Results AFP and CEA in the quality control sera with low and high values were detected by Roche Cobas 6000 automatic electrochemical luminescence analyzer.The coefficient of variations (CV)of inter batch precision were AFP (6.53%,8.38%),CEA (8.15%,7.84%),and the CV of within batch precision were AFP (3.97%,6.51%),CEA (4.77%,4.52%),respectively.10 copies of laboratory quality control were analyzed,issued by the National Center for clinical laboratory in 2013.The largest bias between detection results and“target value”were AFP (-12.62%)and CEA (-10.71%)respectively,which were all within the measurement range of quality assessment.Analysis of measuring range in the linear range experiment were AFP (0.5~1 000 IU/ml),CEA (0.2~1 000 ng/ml),and the clini-cal reportable range were AFP (0.5~1 000 IU/ml),CEA (0.2~1 000 ng/ml),respectively.Conclusion Detection of AFP and CEA from Roche Cobas 6000 automatic electrochemical luminescence analyzer had a good performance.Meanwhile,the Roche Cobas 6000 automatic electrochemical luminescence analyzer could meet the clinical routine testing requirements.
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Objective To verify the performance of HBV detection reagents for Roche MODULRA E170 electrochemical lumi-nescence analyzer .Methods Referring to CLSI EP15-A document ,the minimum detection limit ,linear range ,precision and accuracy of the HBV detection reagents were verified .Results The intra-assay coefficient of variation ,total coefficient of variation ,linear range of HBsAb ,and minimum detection limits of HBsAg and HBeAg of the HBV detection reagents for MODULRA E170 electro-chemical luminescence analyzer all reached the performance claimed by manufacturer .Conclusion The performance of HBV detec-tion reagents for MODULRA E170 electrochemical luminescence analyzer is excellent ,and it can meet the needs of clinical diagnosis and treatment .