水平式琼脂糖凝胶电泳是基因工程操作中最常规的实验方法,它简单易行,只需少量的DNA就能检测,其分辨效果比分光光度计法与溴化乙啶-标准浓度DNA比较法更高,更直接,检测DNA范围更广,其原理是溴化乙啶在紫外光照射下能发射荧光,当DNA样品在琼脂糖凝胶中电泳时,琼脂糖凝胶中的EB就插入DNA分子中形成荧光络合物;使得DAN发射的荧光,增强几十倍。而荧光的强度正比于DNA的含量,如将已知浓度的标准样品做琼脂糖凝胶电泳的对照,就可比较出待测样品的浓度。若用薄层分析扫描仪检测,则可精确地测得样品的浓度。电泳后的琼脂糖凝胶块直接在紫外光下照射拍照,只需5~10ng DNA ,就可以从照片上比较鉴别。如肉眼观察,可检测到0.01~0.1ng的DNA。
From each patient one biopsy was thawed. The thawed tissue was cut into two comparable parts and the wet weight of both parts was measured. Both parts were dried overnight at 100?C, after which they were weighed again in order to measure dry weights. One part was dissolved in nitric acid and consequentially diluted, and sodium content of this solution was mea sured by way of flame spectrometry. The other part was ashed to measure nitrogen via thermal conduction (Dumatherm Nitrogen/Protein analyzer, C. Gerhardt). Nitrogen content of the ashed biopsies was measured as a parameter for protein content of the tissue. This protein content was used to correct for subcutaneous fat, since the assumption was that sodium is stored in skin instead of in fat, and protein is largely absent from fat tissue. Sodium content of the skin is expressed as mmol sodium per mg dryweight or per mg protein.从每个患者中解冻一个活检。将解冻的组织切割成两个可比较的部分,并测量两个部分的湿重。两个部分在100摄氏度干燥过夜,之后再次称重以测量干重。将一部分溶解在硝酸中并随后稀释,并且通过火焰光谱法测量该溶液的钠含量。另一部分用于通过热传导测量氮(格哈特公司 杜马森Dumatherm燃烧法全自动氮/蛋白质测定仪)。测量灰化后的活检的氮含量作为组织蛋白质含量的参数。这种蛋白质含量用于皮下脂肪,因为假设钠储存在皮肤中而不是脂肪中,并且脂肪组织中基本上不存在蛋白质。皮肤的钠含量表示为每mg干重或每mg蛋白质的mmol钠。