Polystyrene Particles Conjugated to Cy5 (20 nm) – Catalog #B2013304

Polystyrene Particles Conjugated to Cy5 (20 nm) (Catalog #B2013304) are brightly fluorescent nanoparticles supplied as a 0.5 mL 1% aqueous suspension. These 20 nm polystyrene beads are covalently labeled with Cy5 (a near-infrared fluorophore with excitation ~649 nm and emission ~670 nm), providing excellent photostability and low background autofluorescence. They serve as powerful tools for fluorescence imaging, flow cytometry, cellular uptake studies, biodistribution tracking, and nanoparticle-based assay development.

Scientific Overview

These 20 nm Cy5-conjugated polystyrene particles combine the excellent optical properties of Cy5 (bright near-infrared fluorescence with minimal tissue autofluorescence) with the stable, inert nature of polystyrene. The covalent conjugation ensures minimal dye leakage, making them ideal for long-term imaging and quantitative tracking. Researchers use them extensively for nanoparticle uptake studies, vascular imaging, lymph node mapping, and as size-calibration standards in fluorescence-based techniques.

Key applications include:

• Live-cell and in vivo fluorescence imaging
• Flow cytometry and FACS sorting
• Cellular internalization and trafficking studies
• Biodistribution and pharmacokinetics of nanoparticles
• Multiplexed assays and instrument calibration

Usage & Handling Guidance

Store at 2–8°C. Do not freeze. Gently vortex or pipette up and down before use to ensure uniform suspension. Dilute in PBS, culture medium, or assay buffer as required. Brief sonication (low power) can be used if minor aggregation occurs after storage.

• Typical working concentration: 10⁵–10⁷ particles/mL (optimize for your assay)
• Excitation/Emission: ~649 nm / ~670 nm (compatible with standard Cy5 filter sets)
• Stability: Stable for months when stored properly; protect from prolonged light exposure

What You Get

• 0.5 mL of 20 nm Polystyrene Particles Conjugated to Cy5 (1% suspension)
• Bright, photostable near-infrared fluorescence
• Uniform size distribution for reproducible results
• Ready-to-use aqueous suspension
• For research use only (RUO)

Why Researchers Choose It

• Bright Cy5 fluorescence in the near-infrared range with low background
• Small 20 nm size ideal for cellular uptake and nanomedicine studies
• Stable covalent conjugation minimizes dye leakage
• Versatile tool for imaging, flow cytometry, and tracking applications
• High-quality biotechnology-grade particles with consistent performance

Frequently Asked Questions (FAQ)

• What are the excitation and emission wavelengths?
  Approximately 649 nm excitation and 670 nm emission (standard Cy5 channel).
• Can these particles be used in live cells or animals?
  Yes. They are commonly used for cellular uptake, trafficking, and in vivo imaging studies.
• How should I store the suspension?
  Store at 2–8°C. Do not freeze. Mix gently before each use.
• Are the particles surface-functionalized?
  These are Cy5-conjugated plain polystyrene particles. Carboxyl- or amine-functionalized versions are available if further conjugation is needed.
• What is the concentration?
  1% (w/v) suspension. Dilute according to your experimental requirements.

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References

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