FAM hydrazide, 5-isomer | CAS 2183440-64-2

FAM hydrazide, 5-isomer is a fluorescein (FAM) hydrazide dye designed for covalent fluorescent labeling through hydrazide reactivity with carbonyl-containing targets. As a fluorescein derivative, it is used to generate bright green fluorescence for microscopy, gel-based readouts, and fluorescence-based assays, with labeling workflows that commonly rely on forming stable hydrazone linkages to aldehyde- or ketone-bearing biomolecules and materials.

1. Carbonyl Biomolecule Labeling

FAM hydrazide, 5-isomer is frequently used in fluorescent labeling of proteins, peptides, and other biomolecules that have been functionalized to introduce aldehyde or ketone groups. Researchers incorporate the dye to create fluorescent conjugates for tracking biomolecule distribution, monitoring binding events, or visualizing labeled targets in analytical workflows such as fluorescence imaging of reaction mixtures and labeled biomolecular assemblies. The hydrazide handle supports covalent attachment, which is valuable when stable signal retention is needed during washing steps and downstream characterization.

2. Fluorescence Microscopy Staining

FAM hydrazide, 5-isomer is applied as a fluorescent stain in microscopy workflows where aldehyde/ketone-bearing surfaces or biomolecular components are present. In cell biology and materials research, it is used to visualize labeled extracellular matrix components, surface-modified biomaterials, and other carbonyl-functionalized structures that can be tagged with fluorescein for spatial localization studies. The dye's fluorescein emission is commonly leveraged for green-channel imaging on standard fluorescence microscopes, enabling convenient visualization of labeled regions after appropriate sample preparation and washing.

3. Fluorescent Gel And Blot Detection

FAM hydrazide, 5-isomer is also used for fluorescence readouts in gel-based analysis when targets are available in carbonyl-functionalized form. Common workflows include fluorescent labeling of biomolecules prior to electrophoresis or post-labeling of carbonyl-containing bands for sensitive visualization with fluorescence imaging systems. This application is particularly useful for researchers who prefer fluorescent detection over colorimetric staining because it supports quantitative imaging of labeled species across gels and membranes using compatible fluorescence scanners.

4. Hydrazone-Labeled Probe Construction

FAM hydrazide, 5-isomer is used in the development of fluorescent labeling reagents and probe constructs where a fluorescein reporter is attached to a carbonyl-containing recognition element or scaffold. Researchers employ the dye to generate fluorescent conjugates for assay development, including labeling of carbonyl-derivatized linkers, affinity reagents, or engineered biomolecular components used in fluorescence-based characterization. The covalent hydrazide-to-carbonyl labeling strategy helps ensure that the fluorescein reporter remains associated with the probe during assay handling and optical readout.