Ludlow J W, Guikema J A, Consigli R A
Anal Biochem. 1986 Apr;154(1):104-9. doi: 10.1016/0003-2697(86)90502-6.
5-(4-Dimethylaminobenzylidene)rhodamine, a silver-specific dye, was used in a colorimetric assay to quantitate the autoradiographic deposition of silver onto X-ray film after exposure to sodium dodecyl sulfate-polyacrylamide gels of radiolabeled biological material. Silver grains were eluted from autoradiograms with 5 N potassium hydroxide, dissolved in nitric acid, and neutralized with 1 M Trizma Base. The concentration of silver was measured spectrophotometrically owing to the chelation properties of the dye. After corrections for background exposure were made, the silver contents of excised bands were then determined by comparison to a standard curve generated with silver nitrate. We have used this silver assay to quantitate the relative amount of each polypeptide band comprising the polyomavirus structural protein VP2 doublet. The method reported here has proven useful when densitometry is inconvenient (i.e., short distance between bands, irregular shape of bands, very faint bands) in addition to being inexpensive and simple to perform.
5-（4-二甲基氨基苄叉）罗丹明是一种银特异性染料，用于比色测定，以定量在暴露于放射性标记生物材料的十二烷基硫酸钠-聚丙烯酰胺凝胶后，银在X射线胶片上的放射自显影片沉积量。用5N氢氧化钾从放射自显影片上洗脱银颗粒，将其溶解在硝酸中，并用1M三羟甲基氨基甲烷碱中和。由于该染料的螯合特性，通过分光光度法测量银的浓度。在校正背景曝光后，通过与用硝酸银生成的标准曲线比较，测定切下条带的银含量。我们已使用这种银测定法来定量构成多瘤病毒结构蛋白VP2双峰的每个多肽条带的相对量。除了成本低廉且易于操作外，本文报道的方法在光密度测定不方便时（即条带之间距离短、条带形状不规则、条带非常淡）已证明很有用。
