Flow Cytometric Analysis of Protein Aggregates.

Area of Science:

• Biophysical Chemistry
• Cell Biology
• Biomolecular Analysis

Background:

• Protein misfolding and aggregation are implicated in neurodegenerative diseases such as Alzheimer's and Parkinson's.
• Characterizing the diverse nature of protein aggregates is crucial for understanding their associated toxicity.

Purpose of the Study:

• To develop and present a novel flow cytometry-based method for characterizing protein aggregates.
• To differentiate protein aggregates based on size and composition, correlating with differential toxicity.

Main Methods:

• Utilized a Beckman Coulter Epics XL flow cytometer with an argon ion laser (488 nm).
• Analyzed autofluorescence, Congo red fluorescence, forward scattering (FSC), and side scattering (SSC) intensities.
• Quantified aggregates up to 20,000 events per sample, with data analyzed using Flowing software and Origin 8.0.

Main Results:

• Autofluorescence and scattering intensities effectively distinguished between amyloid and non-amyloid protein aggregates.
• Dot plots of FSC and SSC provided characteristic fingerprints for different aggregate types.
• Results were comparable to known nanoparticle standards (Fe and Cu oxides).

Conclusions:

• A novel, simple, and robust flow cytometry method for protein aggregate characterization was established.
• This method allows for differentiation based on size and composition.
• The technique has broad potential applications in biomolecular aggregate characterization.