Abstract: DNA was extracted from milk by collecting exfoliative cytology samples from dairy cows. A set of specific primers (α-La-F/R) was designed based on the α-Lactalbumin-encoding gene. A PCR method to detect milk allergens were established by screening the optimum experimental conditions. The results showed that the optimum PCR conditions were 56.5 ℃, 0.15 μmol/L and 35 for annealing temperature, primer concentration and number of cycles, respectively. The PCR method was highly specific and its sensitivity was 0.04 ng DNA. The PCR results of 10 types of commercial dairy products were identical to those described in the product label, suggesting this method to be accurate, reliable and thus applicable in practice.

Key words: milk allergen；α-lactalbumin；PCR

摘要： 采用收集牛奶中脱落体细胞的方法提取牛奶DNA,针对牛奶过敏原蛋白α-乳白蛋白基因序列设计引物α-La-F/R,筛选适宜的实验条件,建立了检测牛奶过敏原的PCR方法.结果表明:PCR反应的最佳退火温度为56.5℃,引物浓度0.15μmol/L,循环数35,进一步实验表明该方法特异性良好,检测灵敏度可达到0.04ng DNA.将建立的PCR方法应用于10种食品的牛奶过敏原检测,实验结果与商品标示一致,表明该方法具有较高的准确性和可靠性,适用于实际商品中牛奶过敏原的检测.

关键词: 牛奶过敏原；α-乳白蛋白；PCR