rhodaminelabeled

Rhodaminelabeled refers to molecules to which a rhodamine dye has been covalently attached to enable fluorescence detection. Rhodamine dyes, including rhodamine B, rhodamine 110, and tetramethylrhodamine derivatives, are widely used in fluorescence-based assays and imaging because of their brightness and relatively good photostability.

Labeling is typically achieved through established chemistries that target common functional groups on the biomolecule. NHS ester or sulfonyl chloride derivatives react with primary amines on proteins or peptides; maleimide dyes react with thiols; certain rhodamine reagents are equipped for conjugation to nucleic acids or to surface linkers. Sulfonated variants are often used to improve solubility and reduce hydrophobic interactions.

Spectral properties of rhodaminelabeled probes depend on the specific dye, but most rhodamine derivatives are excited around 540–570 nm and emit around 560–590 nm, yielding bright red to orange fluorescence. They tend to be relatively photostable and compatible with standard red-channel instrumentation, though pH sensitivity and dye aggregation can affect performance.

Applications include fluorescence microscopy, flow cytometry, immunofluorescence, DNA and RNA labeling, and biosensors. Rhodaminelabeled probes are used to tag antibodies, oligonucleotides, peptides, and lipids, and they are commonly employed in FRET experiments when paired with compatible donor or acceptor dyes.

Limitations include potential non-specific binding and hydrophobic interactions, possible quenching at high labeling densities, and photobleaching under prolonged illumination. Solubility can be improved with sulfonated variants. Proper controls and spectral planning are important to minimize bleed-through in multicolor experiments.