应用地高辛标记探针方法，筛选噬菌体ｃＤＮＡ文库并克隆ＣＮＴＦ基因，将文库以１００００个／皿的噬斑密度铺皿，待形成肉眼可见的噬斑后覆盖尼龙膜进行原位转移，再行变性、中和、交联等处理。ＰＣＲ法扩增出ＣＮＴＦ探针，随机引物法进行地高辛标记，与处理后的尼龙膜杂交，挑出阳性斑进行第二轮低噬斑密度筛选，得到ＣＮＴＦ单克隆基因片断。此法具有实验操作简单、周期短，探针保存时间长，并可反复使用的特点。 Digoxigenin-labeled probes were used to screen the phage cDNA library and clone the CNTF gene. The library was plated at a plaque density of 10000 cells / dish to form a macroscopically visible plaque covering the nylon membrane for in situ metastasis. Denaturation, neutralization, cross-linking and other treatment. CNTF probe was amplified by PCR method, digoxigenin labeling was performed by random primer method, and then hybridized with the treated nylon membrane. Positive plaques were picked out for the second round of low plaque density screening to obtain the single gene fragment of CNTF. This method has the experimental simple operation, short cycle, the probe storage time is long, and can be used repeatedly.