Widely used in oligonucleotide synthesis, this compound enables the incorporation of a fluorescein label directly into DNA strands during solid-phase synthesis. It is especially valuable in the preparation of fluorescently labeled probes for real-time PCR, fluorescence in situ hybridization (FISH), and molecular beacon applications. The phosphoramidite group allows for efficient coupling on DNA synthesizers, ensuring high labeling efficiency and stability. Once incorporated, the fluorescein tag provides a strong fluorescent signal useful for detection, quantification, and imaging of nucleic acids in various diagnostic and research settings. Its use supports sensitive and specific identification of genetic sequences in complex biological samples.