What is CY5.5?

CY5.5 Dye:

    • Type: Near-infrared (NIR) fluorescent dye molecule used in bioconjugation applications similar to CY5.
    • Excitation/Emission wavelength:
        • Excitation peak: Around 683 nm (red light)
        • Emission peak: Around 703 nm (near-infrared light)

Key advantages of CY5.5:

    • High brightness: Offers strong fluorescence intensity for sensitive detection.
    • Good photostability: Resists fading under light exposure.
    • Convenient conjugate labeling: Can be readily attached to biomolecules like proteins and antibodies.
    • Near-infrared emission: Minimizes background autofluorescence from biological samples,improving signal-to-noise ratio.

Key disadvantages of CY5.5:

    • Requires specialized equipment: Needs NIR-compatible excitation and detection instruments.
    • Cost: More expensive compared to some visible wavelength dyes.

CY5.5 Filters:

    • Purpose: Similar to CY5 filters, they selectively transmit light within the excitation and emission ranges of CY5.5, blocking other wavelengths for improved signal-to-noise ratio.

Specific Filter Profiles:

Excitation Filter:

    • Bandwidth: Choose between narrower bandwidth for higher selectivity (potentially lower signal) or wider bandwidth for higher signal (potentially lower selectivity).
    • Examples:
        • Narrow: Omega Filters XF660-20 (640-680 nm), Chroma Technology ET675/25M (650-685 nm)
        • Wider: Omega Filters XF650-40 (630-690 nm), Chroma Technology ET660/40M (640-700 nm)

Emission Filter:

    • Bandwidth: Same considerations as excitation filter.
    • Examples:
        • Narrow: Omega Filters XF710-20 (690-730 nm), Chroma Technology ET700/75M (685-710 nm)
        • Wider: Omega Filters XF705-50 (680-730 nm), Chroma Technology ET725/50M (700-750 nm)

Dichroic Filter:

    • Combines excitation and emission filtering in one component. Useful for multi-color imaging with different dyes.
    • Examples:
        • Omega Filters Dual-Band Dichroic Filter (Excitation: 628/650 nm, Emission: 685/710 nm)
        • Semrock Cy5/Cy7 Dichroic Beamsplitter (Excitation: 635/650 nm, Emission: 670/720 nm)

Additional Notes:

    • Due to the close spectral properties of CY5.5 and CY5, filters designed for CY5 can often be used effectively with CY5.5 as well. However, for optimal performance, especially when precise spectral separation is crucial, consider filters specifically designed for CY5.5.
    • Consult filter manufacturers for detailed specifications and application support to ensure you choose the best filters for your specific needs.
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