离心超滤法测定蛋白质标记物的放射化学纯度

用高效液相色谱法(HPLC)、三氯醋酸(TCA)沉淀法和超滤法分离测定125I-AAFP(抗过敏融合蛋白)标记物的放射化学纯度(RCP),并对其进行比较。结果表明:三种方法均能有效分离标记物和游离碘,用超滤法、TCA沉淀法和HPLC三种方法测定125I-AAFP低、中、高放射化学纯度,样本的RCP分别为0.62%±0.21%、7.25%±1.38%、0.97%±0.12%,61.58%±0.52%、63.18%±1.98%、63.77%±1.23%,98.89%±0.31%、98.76%±0.41%、98.80%±0.82%。当RCP很低时,超滤法与HPLC法测得的RCP间无明显差异(P0.05),而要低于TCA沉淀法(P0.05);除此之外,三种方法无明显差异(P0.05)。这说明离心超滤法可用于分离测定蛋白质标记物的放射化学纯度。

Determination on Radiochemical Purity of Labelled Protein With Centrifugal Ultrafiltration

To explore the determination of radiochemical purity(RCP)of labelled protein with centifugal ultrafiltration,the radiochemical purity of 125 I-AAFP(anti-allergy fusion pro-tein)was determined and compared by high performance liquid chromatography (HPLC), trichloroacetic acid(TCA)precipitation and centrifugal ultrafiltrations.It shows that three methods can separate the labelled 125 I-AAFP and free iodine-125 efficiently.The lower,mid-dle and higher radiochemical purity of 125 I-AAFP which are determined by centrifugal ultra-filtration,TCA and HPLC respectively are 0.62%±0.21%,7.25%±1.38% and 0.97%± 0.12%;61.58%± 0.52%,63.18%± 1.98% and 63.77%± 1.23%;98.89%± 0.31%, 98.76%±0.41% and 98.80%±0.82%.When RCP of 125 I-AAFP is very lower,the RCP measured with HPLC is not different from that with centrifugal ultrafiltration(P>0.05), whereas lower than that with TCA(P<0.05).Except this,there are no significant differ-ences in the RCP of 125 I-AAFP determined with three different methods (P>0.05).Centrif-ugal ultrafiltrations can be used to determinate the radiochemical purity of labelled protein.