Automation of Ischemia Modified Albumin on Beckman Analyser

摘要

Introduction: Early markers for the diagnosis of acute myocardial ischemia are required before necrosis sets in. Ischemia-Modified Albumin (IMA) is one marker which has been shown to rise early before cell necrosis and has been found to be useful in the diagnosis of acute myocardial ischemia.Aim: The present study was taken up to evaluate the assay of IMA levels using albumin cobalt binding method and to automate the method on Beckman Synchron DxC600 analyser.Materials and Methods: Seventy patient samples received in the clinical laboratory for biochemical analysis were used after analysis of the required parameters. Cobalt chloride (CoCl2) and Dithiothrietol (DTT) solutions in various concentrations were tested keeping one parameter constant at a time. Spectrum scan was performed, λ max was noted and absorbance measured at 5 min, 10 min, 15 min, 20 min, 25 min. After the method was established, within run, day to day precision, recovery and interference experiments were performed to test the method performanceResults: Experiments showed that CoCl2, corresponding to a concentration of 0.641 mmol/l and DTT corresponding to a concentration of 1.6207 mmol/l in the final reaction mixture gave the maximum absorbance at 470nm. The method was found to be linear upto an albumin concentration of 5.5g/dl. Intra-assay coefficient of variation (CV) and Inter-assay CV were 1% and 2.5% respectively. IMA test showed no interference for triglyceride concentration upto 443mg/dl, bilirubin concentrations upto 7.9mg/dl and haemoglobin upto 3g/dl. IMA analysis in paired serum and plasma showed values to be higher in serum compared to heparinised plasma.Conclusion: IMA assay can be performed on Beckman DxC 600 analyser. The sample analysis time is 10 minutes and the turn around time is short and thus acceptable. It can therefore be useful in patients with acute chest pain.