Preparation of a reusable enzyme strip for determination of serum cholesterol
نویسندگان
چکیده
A reusable enzyme strip for the determination of cholesterol was prepared by co-immobilizing cholesterol esterase (CEase), cholesterol oxidase (COD) and peroxidase (POD) onto alkylamine glass beads affixed on a plastic strip by a nonreactive fixative. The co-immobilized enzymes retained 71.42% of initial activity of free enzymes with a conjugation yield of 11.0 mg g beads and showed optimum activity at pH 6.6, when incubated at 32°C for 6 min. The strip was employed for direct determination of total cholesterol in serum. The minimum detection limit of the method was 2.14 mg dL reaction mixture. The within batch and between batch coefficient of variation (CV) were <7.0% and <19.0%, respectively. The serum total cholesterol values as determined by the strip, were in good correlation (r=0.885) with those by commercial enzokit method employing free enzymes. The method is characterized by reuse of co-immobilized enzymes with great ease and unaffected by various serum substances.
منابع مشابه
Covalent immobilization of lipase, glycerol kinase, glycerol-3-phosphate oxidase & horseradish peroxidase onto plasticized polyvinyl chloride (PVC) strip & its application in serum triglyceride determination
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