ChromaLINK® Biotin (DMF Soluble)

Introduction to ChromaLINK Labeling Technology

ChromaLINK Biotin has been engineered to include many novel features. As illustrated in Figure 1, the molecule’s structure contains a bis-arylhydrazone chromophore (a), linked by a PEG3 linker arm (b), to biotin (c). This reagent permits direct spectroscopic quantification of incorporated biotin. The extended PEG3 linker preserves biotin/streptavidin affinity and maintains protein solubility after modification while the succinimidyl ester functional group (d), efficiently modifies lysines in aqueous buffers.

Figure 1. Molecular structure of ChromaLINK Biotin

Labeling of proteins with ChromaLINK Biotin eliminates the need to carry out cumbersome and time-consuming HABA assays often employed to quantify biotin incorporation. Instead, biotin incorporation is quantified by means of a simple spectrophotometric measurement at two wavelengths (A280 / A354). Typical labeling results are illustrated in Figure 2 by spectral overlay scans of four samples. As illustrated, bovine IgG (100 ul @ 5 mg/ml) was labeled at 0, 5, 10, and 15 mole equivalents using ChromaLINK Biotin. Spectral analysis illustrates how easy it is to visualize, confirm, and quantify biotin incorporation.

Figure 2. Superimposed spectra of bovine IgG biotinylated using ChromaLINK Biotin. Various biotin-to-protein mole equivalents (5X, 10X and 15X) were used. Note the UV-signature at 354nm indicating incorporation of biotin. All spectra were scanned on a Molecular Dynamics SpectraMax PlusTM UV-VIS plate reader (220-420 nm).