3,3′,5,5′-Tetramethylbenzidine

硝基蓝四唑（NBT）可与碱性磷酸酶底物5-溴-4-氯-3-吲哚基磷酸盐（BCIP）一起用于蛋白印迹和免疫组织染色程序。这些底物系统产生不溶的NBT二甲终产物，其颜色为蓝至紫色，可以通过视觉观察到。

NBT-BCIP substrate system aids in western blotting and immunohistological staining, producing a blue-purple insoluble end product.

The field of proteomics is continually looking for new ways to investigate protein dynamics within complex biological samples. Recently, many researchers have begun to use RNA interference (RNAi) as a method of manipulating protein levels within their samples, but the ability to accurately determine these protein amounts remains a challenge. Fortunately, over the past decade, the field of proteomics has witnessed significant advances in the area of mass spectrometry. These advances, both in instrumentation and methodology, are providing researchers with sensitive assays for both identification and quantification of proteins within complex samples. This discussion will highlight some of these methodologies, namely the use of Multiple Reaction Monitoring (MRM) and Protein-AQUA.