A New Direct Enzymatic Assay for Determination of Beta-Hydroxybutyrate on Clinical Chemistry Analyzer Platforms
K. Eulberg1 , H. Müller1 , A . Lein1 , B. Cucu 1 , L. von Tietzen und Hennig1 , A. Blanco3 , M . Grimmler1,2
1DiaSys Diagnostic Systems GmbH , Alte Strasse 9, 65558 Holzheim , Germany
2Fresenius University of Applied Science, Limburger Strasse 2, 65510 Idstein , Germany
3Vidan Diagnostics, LLC, 24123 Boerne Stage Road, San Antonio, Texas 78255
Determination of β-hydroxybutyrate [in serum or plasma can be used for the diagnosis and prognosis of diabetic ketoacidosis, alcoholic ketoacidosis and hypoglycemia. Recently the determination of β hydroxybutyrate is also used in neurodegenerative diseases, inhibition of adipocyte lipolysis or tumor progression Identification of ketones β-hydroxybutyrate 78 acetone 2%) and acetoacetat 20%)] in serum is exempt from FDA 510(k) premarket notification procedures. The objective of this study was to evaluate CLSI performance of DiaSys β-Hydroxybutyrate 21 FS reagent on Architect c8000TM clinical chemistry analyzer.
MATERIAL AND METHODS
DiaSys β-Hydroxybutyrate 21 FS is a liquid stable ready to use 2 component assay, based on an UV test principle utilizing the β-hydroxybutyrate dehydrogenase dependent conversion of NAD to NADH. The rate of NADH formation is determined by measuring a specific change of absorbance at 340/700 nm, which is directly proportional to the β-hydroxybutyrate concentration in the sample. Evaluated specimen are sera and heparin plasma.
Performance evaluation of DiaSys β-Hydroxybutyrate 21 FS on Architect c8000TM clinical chemistry analyzer revealed a wide linearity range from 0.05 mmol/L up to 8 mmol/L due to a specially adjusted application [Fig.1]. Comparative studies with a commercially available enzymatic colorimetric assay according to CLSI protocol [EP09-A3] show a good correleation of: r=0 9.991; y=1.012 x 0.001 mmol/L using regression analysis according to Passing and Bablok [Fig.2]. Moreover, DiaSys β-Hydroxybutyrate 21 FS is highly precise with a repeatability of 2.06 [Fig.3] and a total precision according to CLSI protocol [EP05-A2, EP15 A2] of 3.11% [Fig.4]. In addition the assay shows a high onboard and calibration stability of at least 10 weeks [Fig.5], also interferences like ascorbic acid, hemoglobin or bilirubin are minimized [Fig.6].
DiaSys β-Hydroxybutyrate 21 FS is well applicable on Architect c8000TM clinical chemistry analyzer and shows outstanding performance especially for linearity and precision. The performance of the test is highly competitive in comparison to already available products in the market and very well suited for diagnosis and monitoring of patients with diabetes to prevent ketoacidosis.
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