SYPRO Orange - a new gold standard amyloid probe

Area of Science:

• Biochemistry
• Molecular Biology
• Medical Imaging

Background:

• Amyloid fibrils are protein aggregates implicated in various neurodegenerative diseases.
• Current diagnostic probes for amyloid fibrils, such as thioflavin T, have limitations in sensitivity and spectral properties.
• Development of novel, highly sensitive probes is crucial for early disease detection and monitoring.

Purpose of the Study:

• To introduce and characterize SYPRO Orange, a new zwitterionic merocyanine dye, as a sensitive probe for amyloid fibrils.
• To compare the performance of SYPRO Orange with the gold standard probe, thioflavin T.
• To evaluate the suitability of SYPRO Orange for in vivo imaging applications.

Main Methods:

• SYPRO Orange, a zwitterionic merocyanine dye, was synthesized and characterized.
• Interaction of SYPRO Orange with pre-formed amyloid fibrils was studied using fluorescence spectroscopy.
• Emission intensity changes upon binding were quantified.
• Sensitivity and spectral properties were compared to thioflavin T.
• In vitro and in vivo imaging potential was assessed.

Main Results:

• SYPRO Orange exhibits strong binding to amyloid fibrils, resulting in a significant (approximately 1200-fold) increase in emission intensity.
• The sensitivity of SYPRO Orange is several times higher than that of thioflavin T.
• SYPRO Orange possesses spectral properties advantageous for in vivo imaging.
• Detection sensitivity in the picomolar range was achieved.

Conclusions:

• SYPRO Orange is a highly sensitive and effective fluorescent probe for detecting amyloid fibrils.
• Its superior sensitivity and spectral characteristics make it a promising alternative to thioflavin T for both in vitro and in vivo applications.
• SYPRO Orange holds potential for advancing the diagnosis and study of amyloid-related diseases.