In biomedical research and advanced diagnostics, the conjugation of fluorochromes to proteins plays a key role in the accurate detection of biomolecules. Two essential reagents in these assays are FITC-Streptavidin and PE-Streptavidin, designed to facilitate specific binding to biotinylated molecules, enabling highly sensitive detection in applications such as flow cytometry, ELISA, immunohistochemistry and other fluorescence-based assays.
Why use Streptavidin conjugate?
Streptavidin is a protein with a very high affinity for biotin, forming an extremely stable complex. Thanks to this property, its conjugation with fluorochromes allows accurate detection of biotinylated molecules without significant interference. Depending on the type of fluorochrome used, different advantages in sensitivity and spectral separation can be obtained.
FITC-Streptavidin: High sensitivity in green channel
FITC-Streptavidin is conjugated to fluorescein isothiocyanate (FITC), a widely used fluorochrome due to its signal intensity and compatibility with numerous flow cytometers and fluorescence microscopes. Its main features include:
-Excitation: 488 nm
-Emission: 519 nm (green channel)
-High stability and low background noise
-Ideal for immunofluorescence assays and biotin detection in cells and proteins.
PE-Streptavidin: higher fluorescence intensity in the red-orange channel
PE_Streptavidin, conjugated to phycocyanin-R (PE, Phycoerythrin), is an excellent choice for applications where more intense fluorescence and higher signal-to-noise ratio are required. Its main advantages include:
-Excitation: 496-5656 nm (optimal with 488 nm and 561 nm lasers).
-Emission: 578 nm (red-orange channel)
-Higher brightness than FITC, ideal for detection of low expressed biomolecules.
-Wide applicability in flow cytometry and immunofluorescence
Which one to choose for your experiment?
The choice between FITC-Streptavidin and PE-Streptavidin depends on several factors, including the required sensitivity, instrument configuration and the need to minimize spectral overlaps. Here are some recommendations:
-If you need a moderate fluorescence marker that is compatible with most equipment, FITC-Streptavidin is the best choice.
-If you are looking for a brighter signal and less interference in the emission spectrum, the PE-Streptavidin is the ideal alternative.
-For multi-parameter studies, combining the two allows for more efficient detection in different channels.
Conclusion
Both FITC-Streptavidin and PE-Streptavidin are key tools in the detection of biotinylated molecules. Their strategic use in flow cytometry, ELISA and immunofluorescence assays allows for reliable and highly reproducible results. At Immunostep, we offer the highest quality reagents to ensure accuracy in your research, so explore our options and optimize your experiments with the best fluorescent conjugate technology!