The peroxidase enzyme was extracted by juicing the turnip roots followed by centrifugation at 12000 rpm. Partial purification of the enzyme was carried out by precipitating of crude enzyme solution with solid (NH4)2SO4 and dialyzed against phosphate buffer saline (PBS) then fractionated by gel filtration on Sephadex G-75 column. The fractionation pattern of the pre-dialyzed enzyme illustrated that two peaks of protein content (absorbance at 280 nm) were present. The 1st peak contained most of the peroxidase activity. The 2nd peak contained other proteins. The enzyme activity showed 2.5 Ku/1ml when guaicol was used as a substrate. For glucose clinical diagnostic kit, two reagents were prepared: The 1st was commercial glucose kit as control. The 2nd was completely prepared using the extracted peroxidase (100 units/100ml reagent). The stability of the prepared kits was in agreement with those of commercial kit. They were stable up to one year when tested corresponding to the reference range of glucose; Normal: 74-102 mg/dl and Pathogenic: 235-325mg/dl.
Peroxidase, Turnip, Extraction, Purification, and clinical diagnostic kit