Wong P Y, Cheung M, Yip T K, Mee A V
Clin Chem. 1986 Mar;32(3):492-5.
We synthesized an 125I-labeled-histamine-cyclosporin C tracer, to obviate the use of tritiated tracer in radioimmunoassay of cyclosporine. With this tracer, the assay results varied linearly with concentration up to at least 800 micrograms/L. The within-assay CV was 6.6% at 39 micrograms/L, 4.2% at 100 micrograms/L, and 7.0% at 300 micrograms/L (n = 15). The between-assay CV was 10.0, 6.4, and 7.8% for the same respective concentrations. Comparison with an assay involving tritiated tracer (x) showed good agreement of results: y = 3.81 + 0.927x (r = 0.975, n = 604). Analytical recovery ranged from 100 to 106%. We also compared another commercially available radioiodinated tracer ("125Iodocyclosporin"; Immunonuclear Corp.). Our tracer appeared to be more specific for cyclosporine, as determined by assaying chromatographic fractions of bile extract from a patient being treated with cyclosporine. Results with use of our tracer compared favorably with those obtained with the tritiated tracer, and our assay has the advantages of gamma counting vs liquid-scintillation counting.
我们合成了一种125I标记的组胺-环孢素C示踪剂，以避免在环孢素放射免疫分析中使用氚标记示踪剂。使用这种示踪剂，测定结果在浓度高达至少800微克/升时呈线性变化。批内变异系数在39微克/升时为6.6%，在100微克/升时为4.2%，在300微克/升时为7.0%（n = 15）。相同相应浓度下的批间变异系数分别为10.0%、6.4%和7.8%。与涉及氚标记示踪剂（x）的分析比较显示结果具有良好的一致性：y = 3.81 + 0.927x（r = 0.975，n = 604）。分析回收率在100%至106%之间。我们还比较了另一种市售的放射性碘化示踪剂（“125Iodocyclosporin”；免疫核公司）。通过对一名接受环孢素治疗患者胆汁提取物的色谱馏分进行分析测定，我们的示踪剂似乎对环孢素更具特异性。使用我们的示踪剂得到的结果与使用氚标记示踪剂得到的结果相比更有利，并且我们的分析具有γ计数相对于液体闪烁计数的优势。
