目的 建立并验证重组人干扰素α1b等电点（isoelectric point，pI）全柱成像毛细管等电聚焦电泳（imaging capillary isoelectric focusing electrophoresis，iCIEF）检测方法。方法 用iCIEF检测重组人干扰素α1b的pI，对iCIEF的样品中尿素添加浓度以及等电聚焦时间进行确认，并依据人用药品技术要求国际协调理事会Q2（R2）要求对该检测方法进行方法学验证，包括专属性、准确度、重复性、中间精密度和耐用性。结果 最终选择等电聚焦条件为3 000 V等电聚焦3 min，样品检测时添加尿素终浓度为1 mol/L。空白对照（醋酸盐缓冲液）对重组人干扰素α1b pI的检测没有干扰，重组人干扰素α1b等电聚焦产生2个峰，峰1 pI约为5.4，峰2 pI约为5.5；经验证该检测方法专属性、准确度、重复性、中间精密度和耐用性均良好。结论 建立的iCIEF检测方法可以用于重组人干扰素α1b pI的检测，可为该产品的质量控制提供参考。

Objective To develop and validate the isoelectric point (pI) detection method for recombinant human interferon α1b (rhIFNα1b) by imaging capillary isoelectric focusing electrophoresis (iCIEF).Methods Based on The International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use Q2 (R2) requirement, iCIEF was used to detect the pI of rhIFNα1b, and the concentration of urea added to sample and isoelectric focus time were determined.The developed method was verified for specificity, accuracy, repeatability, intermediate precision and durability.Results In iCIEF, the focusing was performed at 3 000 V for 3 min, and 1 mol/L urea was added to treat samples. Blank control (acetate buffer) showed no interference to the determination of pI of rhIFNα1b. Isoelectric focusing of rhIFNα1b generated 2 peaks. The pIs of peak 1 and 2 were approximately 5.4 and 5.5, respectively. The method had good specificity, accuracy, repeatability, intermediate precision, and durability.Conclusion This established iCIEF method can be used for the detection of the pI of rhIFNα1b, providing a reference for the quality control of this product.