EXCEL - EXtracellular particle Characterization and Enrichment Lab

Overview of Services

Welcome to EXCEL (Extracellular Particles Characterization and Enrichment Lab) – the EV Core Facility dedicated to advancing research in extracellular vesicles (EVs) and other nanoparticles.

EVs are gaining prominence not only in basic cell biology but also as platforms for biomarkers and therapeutics. Our facility offers comprehensive services to support your research needs:

Consultation Services

• Experimental Design Consultation
  • We provide guidance to ensure your study complies with international consensus standards for EV research, such as the Minimal Information for Studies of EVs (MISEV). This includes advice on sample collection and pre-processing.
• MISEV Package
  • To facilitate adherence to MISEV guidelines, we offer a comprehensive MISEV Package that includes standardized protocols, documentation templates, and best practices to ensure your EV studies meet the highest standards of reproducibility and transparency.

EV Separation Techniques

Our suite of separation techniques can be performed individually or sequentially:

• Size Exclusion Chromatography (SEC)
  • Fast Protein Liquid Chromatography (FPLC)
  • Gravity-based methods using Izon pre-packed columns with automated fraction collectors
• Tangential Flow Filtration (TFF)
• Differential Ultracentrifugation (dUC)
• Density Gradient Ultracentrifugation (dgUC)
• Affinity Separations

EV Characterization Approaches

Utilizing state-of-the-art technologies, we offer a range of characterization methods:

• Resistive Pulse Sensing (RPS) – Spectradyne
• Nanoparticle Tracking Analysis (NTA) – ZetaView
• Nano-Flow Cytometry – NanoFCM, Cytoflex Nano (coming soon!)
• Interferometric Imaging with Immunophenotyping (SP-IRIS) – ExoView/Leprechaun
• Transmission Electron Microscopy (TEM)
• Super-Resolution Microscopy – ONI
• Multiplexed Ultrasensitive ELISA – Meso Scale Discovery

Several of these techniques are ideal for cutting-edge single-particle phenotyping.

Standard Characterization Methods

• Western Blotting
• ELISA
• Protein, Lipid, and Nucleic Acid Quantification

Comprehensive Molecular Profiling

• Proteins and RNA
  • In collaboration with existing Johns Hopkins cores, we offer services and advice for in-depth molecular profiling.

Post-Separation Consultation

• We provide expert guidance on investigating EVs after separation and characterization to maximize the impact of your research findings.

Leadership

Kenneth Witwer, PhD, Director

Olesia Gololobova, PhD, MEng, Manager

Location and hours of operation

Contacts

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