摘要
目的 建立一种特异性更高的酶法血清结合胆红素 (CB)测定的新方法。方法 在pH5 5、有氟化钠 (NaF)和N 乙酰半胱氨酸 (NAC)的存在下 ,胆红素氧化酶 (BOD)选择性氧化CB ,引起 4 5 0nm吸光度下降 ,计算CB的浓度。结果 批内精密度 ,n =2 0 , x =17 6 5 μmol/L ,s =1 15 ,CV =6 5 2 %和 x =30 1 4 9μmol/L ,s =1 0 1,CV =0 33% ;批间精密度 ,n =2 0 , x =31 5 0 μmol/L ,s =3 12 ,CV =9 90 %和 x =184 12 μmol/L ,s =5 0 1,CV =2 72 % ;线性范围至少可达 32 0 μmol/L ;选择性抑制物的最适浓度 ,NaF 2 5mmol/L ,NAC 2 5mmol/L ;与重氮法的相关性 ,Y (酶法 ) =0 839X (重氮法 ) - 7 96 5 ,r=0 96 90。结论 该研究建立的反应条件 ,能有效地抑制BOD对游离胆红素的“非特异性”氧化 ,提高CB测定的准确性。
Objective To establish a new enzymatic method for the determination of serum conjugated bilirubin (CB) by the use of bilirubin oxidase (BOD). Method Only the CB was oxidized by BOD under the conditions of pH 5.5 in the presence of sodium fluoride NaF and N-acetylcysteine (NAC) which could prevent the unconjugated and delta bilirubin oxidized. CB was quantitatively determined from a decrease in the absorbance at 450 nm caused by CB oxidization. Results The intra-assay CVs were 6.52% and 0.33% (n=20) at CB concentrations of 17.65 and 301.49 μmol/L, respectively. The inter-assay CVs were 9.90% and 2.72% at 31.50 and 184.12 μmol/L, respectively. The linearity was up to 320 μmol /L. The optimum concentrations of selective inhibitors were 2.5 mmol/L for NaF and 2.5 mmol/L for NAC. The results of serum CB (Y) determined by this method correlated well with those determined by diazo-dye method (Y=0.839X-7.965, r=0.969). Conclusion The proposed reaction conditions could effectively inhibit the oxidation of unconjugated bilirubin by BOD, and thus increase the specificity of CB assay.
出处
《中华检验医学杂志》
CAS
CSCD
北大核心
2003年第4期207-210,共4页
Chinese Journal of Laboratory Medicine
