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采用ＥＮＵ（乙基亚硝基脲）作用于裸露的λｇｔ１１ＤＮＡ，经体外重包装，转染宿主菌ＥｃｏｌｉＹ１０９０，在含底物Ｘ－ｇａｌ，诱导剂ＩＰＴＧ的选择性培养基上铺皿，发现被处理的λｇｔ１１ＤＮＡ除了使噬菌体存活率下降外，还出现了靶基因“ＬａｃＺ”较高频率的突变。其中以二甲基亚砜（ＤＭＳＯ）为溶剂，当存活率分别为３５×１０－３、１６×１０－３和５５×１０－４时，相应的突变率依次为１１×１０－３、３２×１０－３和５２×１０－３，ＤＭＳＯ溶剂对照突变率则＜５０×１０－５。对ＥＮＵ诱导的５个阳性突变体进行了扩增，以ＰＣＲ产物为模板，采用正向引导，对阳性突变体靶基因ＬａｃＺ进行了部分测序，在被测序的２６０ｂｐ范围内，发现了９个位点的碱基突变。碱基突变的类型有颠换（６７％）、转换（１１％）和移码突变（２２％）。颠换主要以Ａ→Ｔ、Ｇ→Ｃ为主。似乎胞嘧啶（Ｃ）更易发生突变（占４３％）。
ENU (ethylnitrosourea) was used to act on naked λgt11 DNA. The recombinant plasmid was in vitro re-packaged and transfected into host strain E.coliY1090. The recombinant plasmid was plated on selective medium containing substrate X-gal and inducer IPTG and found that In addition to reducing the viability of the phage, the λgt11 DNA treated also showed a higher frequency of mutation of the target gene “LacZ”. When DMSO was used as the solvent, the survival rates were 35 × 10-3, 16 × 10-3 and 55 × 10-4, respectively, and the corresponding mutation rates were 1 1 × 10-3,3 2 × 10-3 and 5 2 × 10-3, DMSO solvent control mutation rate <5 0 × 10-5. Five positive mutants induced by ENU were amplified. PCR products were used as a template. Positive primers were used to sequence LacZ, a positive mutant target. Within the range of 260 bp, nine loci were found Dot base mutation. The types of base mutations are transversion (67%), conversion (11%) and frameshift mutations (22%). Transversion mainly A → T, G → C-based. It appears that cytosine (C) is more susceptible to mutation (43%).