Quantitative Seed Amplification Assay: A Proof-of-Principle Study.

Area of Science:

• Biochemistry
• Neuroscience
• Medical Diagnostics

Background:

• Alpha-synuclein (αS) amyloid fibrils are key biomarkers for Parkinson's disease (PD).
• Seed amplification assays (SAAs) detect αS fibrils in biofluids like CSF for PD diagnosis.
• Quantifying αS fibrils is challenging but vital for assessing PD progression and severity.

Purpose of the Study:

• To establish a proof-of-principle for quantifying αS fibrils using SAAs.
• To assess the feasibility of αS fibril quantification in complex biomatrices, including blood serum.
• To investigate the impact of biomatrix components on SAA performance.

Main Methods:

• Utilized standard SAAs to analyze αS fibrils in spiked model solutions.
• Varied the compositional complexity of model solutions, including diluted blood serum.
• Investigated interactions between monomeric αS and biomatrix components like human serum albumin.

Main Results:

• Standard SAA parameters enabled αS fibril quantification in complex solutions.
• Identified and accounted for interactions between monomeric αS and biomatrix components.
• Achieved quantification of αS fibrils down to the single fibril level in spiked diluted blood serum.

Conclusions:

• Quantitative SAAs are feasible for measuring αS amyloid fibrils.
• This method holds promise for monitoring Parkinson's disease progression and severity.
• The approach is adaptable for detecting αS fibrils in challenging biofluids like blood serum.