• Korean Journal of Clinical Laboratory Science
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• v.39 no.3
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• pp.196-200
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• 2007

In clinical practice, homocysteine has gained popularity because its elevated values are strongly associated with an increased risk of cardiovascular disease. More recently, a new enzymatic colorimetric assay for homocysteine in biological sample, suitable for automated clinical analyzers, has been proposed. To evaluate one of these enzymatic methods and compare the results obtained with this method with those of an immunoenzymatic method, thirty-two samples were analyzed for total homocysteine by HiSens$^{(R)}$ homocysteine reagent on the automated chemistry analyzers TBA 200FR and compared to the widely used immunoenzymatic method ADVIA Centaur. In TBA 200FR, the within-run CVs of two control materials were 3.23% and 0.92%, respectively; the between run CVs were 4.58% and 2.55%, respectively. And in ADVIA 1650, the within-run CVs were 6.81% and 0.99%, respectively; the between run CVs were 9.0% and 3.9%, respectively. The recovery for homocysteine was 100% ($60.8{\mu}mol/L$), 99.1% ($48.64{\mu}mol/L$), 96.3% ($36.48{\mu}mol/L$), 96.1% ($24.32{\mu}mol/L$), and 92.1% ($12.16{\mu}mol/L$). The regression equation of TBA 200FR vs. ADVIA Centaur was y=0.9095x-2.5086 (r=0.9632). And the regression equation for the ADVIA 1650 chemistry vs. Immulite 2000 was y=0.8418x + 0.3207 (r=0.9625). In conclusion, this enzymatic method using automated chemistry analyzer for homocysteine assay shows acceptable analytical performance. I suggest that this assay will be suitable for routine analysis.

• Laboratory Medicine Online
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• v.2 no.1
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• pp.10-14
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• 2012

Background: Measurement of HbA_1c levels is widely used to diagnose diabetes mellitus and to evaluate and monitor plasma-glucose concentrations over 6-8 weeks. In this study, we evaluated the diagnostic performance of the newly developed latex immunoturbidimetric method by using Autolab HbA_1c. Methods: We analyzed and compared the diagnostic performance of Autolab HbA_1c with that of Toshiba 200FR between April 2009 and July 2009. According to guidelines (EP5-A2, EP6-P, EP9-A2) of the clinical and laboratory standards institute (CLSI), we compared linearity, precision and correlation of Autolab HbA_1c with those of G7 (Tosoh Corp., Kyoto, Japan) by using high-performance liquid chromatography (HPLC) method. Results: Data obtained using Autolab HbA_1c showed good linearity in mixtures of samples with low (3.1%) and high (15.1%) levels of HbA_1c (r²=0.9997). In the analysis of within-run precision of the samples with HbA_1c levels of 5.1% and 12.1%, the SDs were 0.04 and 0.06 and covariances of these samples were 0.8% and 0.5%, respectively. In the Deming regression model, the regression equation was as follows: Autolab HbA_1c=1.0859×Tosoh HPLC-0.6957. Conclusions: In this study, Autolab HbA_1c method showed better performance characteristics than Tosoh G7 did. In reference review, there was no interference of variant hemoglobin. The data acquisition time of Autolab HbA_1c was lower than that of Tosoh G7. The advantages of Autolab HbA_1c are that it can be used as an autoanlyzer in routine chemical analysis, it does not require pre-analytical treatment, and the samples are automatically treated with distilled water for hemolysis.