Overview
Cy3-β-Ala is a fluorescent dye conjugate combining the cyanine dye Cy3 with β-alanine, an amino acid derivative. This modification enhances the dye's water solubility and reduces aggregation, making it particularly useful for biological applications. The compound is part of the cyanine dye family, known for their bright fluorescence and stability. The conjugate is widely used in life sciences for labeling biomolecules such as proteins, peptides, and nucleic acids. Its excitation and emission maxima are around 550 nm and 570 nm, respectively, making it compatible with common fluorescence detection systems. Its popularity stems from its combination of performance characteristics and relatively low photobleaching compared to some other dyes.
Physical and Chemical Properties
Cy3-β-Ala appears as a dark red to purple solid with good solubility in organic solvents like DMSO and DMF, and moderate solubility in aqueous buffers. The β-alanine linker improves water solubility compared to the parent Cy3 dye, which is particularly beneficial for biological applications where aqueous conditions are common. The dye exhibits strong absorbance in the visible spectrum with high molar extinction coefficients, typically >150,000 M-1cm-1. Its fluorescence quantum yield is generally in the range of 0.1-0.3 depending on the environment. The compound is moderately stable to light and heat but should be protected from prolonged exposure to strong light sources to prevent photodegradation.
Main Applications
The primary use of Cy3-β-Ala is as a fluorescent label in various biological detection and imaging techniques. It's commonly employed in fluorescence microscopy for cellular imaging, where it can be conjugated to antibodies for immunostaining or to other targeting molecules. The dye is also used in flow cytometry for cell population analysis and sorting. In molecular biology applications, Cy3-β-Ala is used to label nucleic acids for techniques like fluorescence in situ hybridization (FISH) and real-time PCR detection. Its relatively small size compared to some fluorescent proteins makes it useful for studying biomolecular interactions where minimal steric interference is desired. The dye is also employed in microarray technologies and some diagnostic assays.
Safety and Storage
Cy3-β-Ala should be handled with standard laboratory precautions. While not classified as highly toxic, it may cause irritation upon contact with skin or eyes. Appropriate personal protective equipment including gloves and safety glasses should be worn when handling the compound. For long-term storage, the dye should be kept at -20°C in the dark, preferably under an inert atmosphere to prevent oxidation. Small working aliquots are recommended to minimize repeated freeze-thaw cycles. Solutions of the dye are generally stable for several weeks when stored at 4°C in the dark, but should be protected from microbial growth if stored for extended periods.
B2B Procurement Guide
When procuring Cy3-β-Ala for research or commercial applications, buyers should pay attention to several key factors. Purity is critical, with most applications requiring ≥95% purity as determined by HPLC. Batch-to-batch consistency is also important for reproducible results in sensitive applications. Consider the supplier's reputation and quality control measures, especially for applications requiring regulatory compliance. Some suppliers offer custom conjugation services which may be valuable for specific applications. For bulk purchases, verify stability data and consider requesting a certificate of analysis for each batch. Some manufacturers offer different packaging options which can be important for minimizing waste in low-throughput applications.