FAM-xtra Phosphoramidite | CAS 2304636-67-5

FAM-xtra Phosphoramidite is a fluorescein (FAM) phosphoramidite building block designed for fluorescent labeling of nucleic acids during automated solid-phase oligonucleotide synthesis. This reagent enables incorporation of a fluorophore directly into DNA or RNA probes, primers, and molecular beacons, supporting fluorescence readouts in nucleic acid analysis workflows. Its phosphoramidite functionality is tailored for standard oligonucleotide coupling chemistry, making it a practical choice for researchers developing fluorescence-based hybridization and amplification assays.

1. Oligonucleotide Fluorescent Labeling

FAM-xtra Phosphoramidite is used to introduce a fluorescein fluorophore into DNA or RNA oligonucleotides for fluorescence-based nucleic acid workflows. Researchers commonly incorporate it during automated synthesis to generate labeled primers, hybridization probes, and sequence-specific detection oligos used in assay development and method optimization. The resulting FAM-tagged oligonucleotides are then used for fluorescence imaging, plate-based readouts, and analytical gel or capillary workflows where the fluorophore provides a direct optical signal tied to sequence identity.

2. Molecular Beacon Probe Construction

FAM-xtra Phosphoramidite supports the construction of FRET-enabled molecular beacons by enabling site-specific placement of a fluorescein donor within the beacon sequence. In nucleic acid sensing formats, these probes are designed so that target-dependent hybridization changes the fluorescence output, allowing researchers to monitor nucleic acid presence or hybridization events in solution. Typical users include molecular biology groups and assay developers who build beacon libraries for screening probe architectures and reaction conditions in fluorescence-based detection experiments.

3. Fluorescent Hybridization Assays

FAM-xtra Phosphoramidite is applied to create fluorescently labeled hybridization probes used for detecting complementary nucleic acid targets in research and industrial R&D settings. Labeled probes generated from this phosphoramidite are used in assay formats where fluorescence intensity reports on hybridization, enabling readouts compatible with common fluorescence plate readers and imaging systems. This reagent is particularly relevant when a defined fluorophore position within the oligonucleotide is required to tune probe performance for downstream hybridization workflows.

4. Primer Labeling For PCR Workflows

FAM-xtra Phosphoramidite is used to prepare fluorescently labeled primers for nucleic acid amplification experiments and fluorescence-based monitoring strategies. By incorporating fluorescein into primer oligonucleotides during synthesis, researchers can generate amplification reagents that yield a direct fluorescence signal associated with primer extension and product formation. This approach is commonly used in method development and assay prototyping where fluorescently tagged oligos are needed to support optical readout of nucleic acid reactions.