快速检测牛奶中体细胞数方法的改进

Improvement of a Rapid Determination Method of Somatic Cells Count in Milk

为探求1种简单、快速、准确的牛奶体细胞数测定方法,将牛奶样品经表面活性剂十二烷基硫酸钠处理后,奶样中体细胞的细胞膜和核膜被破坏,细胞核DNA大量释放,引起奶样稠度发生很大的变化,可用Lamb-lewis稠度计测量其稠度的变化。通过分析缓冲液pH、处理时间、温度等条件对奶样稠度的影响,结果表明,在一恒定温度条件下,缓冲液pH7.5、处理时间15～20min时,乳样体细胞数与SDS处理后奶样稠度之间存在显著的线性关系;通过测定SDS处理后奶样的稠度,可以快速、准确地检测出其中的体细胞数。

For seeking a rapid, simple and accurate method to determinate SCC in milk, a rapid determination method was studied based on consistency. After treatment with SDS, both membrane of the somatic cells and its nuclear were disrupted, which leads to much of DNA be released from the nuclei and the consistency of the milk sample changed. Iamb-lewis viscometer was used to determine the consistency of the treated milk sample. The effects of buffer pH, time of treatment and temperature on the consistency of the milk sample were investigated. The highest consistency was observed at pH 7.5-8.0. After treatment of 15 min, the consistency was constant. A significant positive linear correlation between SCC and consistency was obtained at 25℃, 30℃, 35℃, 40 ℃ with correlation coefficient 0.9930, 0. 9871, 0.9895, 0.9924 （p〈0.01）. Results suggested that milk SCC could be determined by measuring of consistency of the milk sample under the condition of constant temperature, buffer pH 7.5 and treatment time 15-20 min. This method will be simple, rapid and accurate.