对磁珠吸附过程中三羟甲基氨基甲烷-乙二胺四乙酸(Tris-EDTA,TE)缓冲液的pH值、蛋白酶K添加量、吸附时间和吸附温度等参数进行了优化。在优化条件下氨基磁珠可以非特异性地直接吸附婴幼儿配方奶粉中存在的脱氧核糖核酸(deoxyribonucleic acid，DNA)，并结合聚合酶链式反应(polymerase chain reaction，PCR)技术特异性扩增阪崎克罗诺杆菌DNA，检测灵敏度达到102 CFU/mL。此外，经特异性试验验证，此方法用于检测常见食源性致病菌及克罗诺菌属中的非阪崎克罗诺杆菌均无交叉反应。同时，经干扰性试验验证，体系中存在的其他干扰菌株DNA并不会影响阪崎克罗诺杆菌的检测。该方法避免了抗体的使用，解决了抗体制备难度大、成本高等问题，同时克服了传统方法3～5 d前增菌时间过长的弊端，实现了对婴幼儿配方奶粉中阪崎克罗诺杆菌的快速检测。

The pH value of TE buffer, proteinase K addition, absorption time and temperature were optimized during the absorption process. Under optimized conditions, a trace amount of genomic DNA of one or more types of pathogens can be adsorbed directly by amino magnetic nanoparticles in powdered infant formula (PIF). Combined with specific amplification of Cronobacter sakazakii by PCR identification, the detection sensitivity can reach 102 CFU/mL. Besides, the control test based on this method showed a stronger specificity of common food borne pathogens and the main species of Cronobacter spp.. And the interference test proved that DNA of other interfering strains did not affect the detection of C. sakazakii. This method avoided the use of antibodies, solved the problems of difficult preparation and high cost of antibody, overcame the long pre-enrichment incubation time of traditional method and facilitated the rapid detection of C. sakazakii in PIF.