Protein modification (in particular, labeling proteins with different reporter groups) is an essential task in biological sciences. AnaSpec offers a variety of high quality reactive fluorescent dyes for labeling proteins such as antibodies. We also offer a variety of biotins with different reactive groups for protein modifications. These high quality stand-alone reagents can be used by experienced researchers to readily label a variety of proteins and other biomolecules. Labeled proteins can be used in a number of applications, such as immunological assays, fluorescence microscopy, investigation of protein-protein interactions, etc.