Multisizer 4e Coulter Counter
The Multisizer 4e particle sizer and counter is the most accurate and flexible particle characterization device available, boasting an unparalleled sizing range of 0.2 - 1600 μm. The new 10 μm Aperture allows users to study sub-cellular and micro-particles as small as 200 nm, while the advanced noise reduction system for small apertures improves measurement accuracy.
Generated data are processed using patented digital pulse processing technology and can be saved and later re-analyzed. This technology provides ultra-high resolution and accuracy unattainable through any other technologies: detection of 1 particle in 1 ml of a sample with the optimal instrument configuration. Analysis results are not dependent on particle shape, structure, or optical properties.
It uses the Coulter principle to detect particles via electrical zone sensing, regardless of the particle’s nature or optical properties. This makes it an ideal tool for detecting and counting a wide variety of particles, such as:
- Mammalian cells
- Bacteria
- Yeast
- Abrasives
- Toner particles
- Cell aggregates
- Spheroids
- Large protein aggregates
Additional Multisizer 4e Coulter Counter Resources
- Application Note: Optimizing the Multisizer 4e Coulter Counter for Use with Small Apertures
- Application Note: Cellular Analysis Using the Coulter Principle
Multisizer 4e Coulter Counter Features
Versatility
- Aperture sizes from 10 µm - 2000 µm in diameter for current & future needs
- Multiple aperture options & data overlay capability for analyzing complex samples over wide particle size distribution
Sample Detection
- Analyze materials in aqueous or non-aqueous solvents
- Ideal for biological or non-biological samples
- Detect particles regardless of material type or optical properties
Rapid Particle Counting
- Typical sampling rates up to 10,000 counts per second
- Detect & count particles from 0.2 µm - 1600 µm in diameter
- Sample volumes as small as 5 mL
Data Management
- Digital pulse data can be stored & re-analyzed as needed
- 21 CFR Part 11 compliant software for audit control & security
- Variety of calibration beads & V-check validation controls
Explore Multisizer 4e Coulter Counter Models
Technical Documents
Multisizer 4e Particle Analyzer
What is the Coulter principle for particle analysis?
The Coulter principle is a widely used method for particle size and count analysis based on electrical resistance. It works by suspending particles in a conductive liquid and passing them one by one through a small aperture with an electrical current applied.
When a particle passes through the aperture, it displaces its own volume of electrolyte, causing a momentary change in electrical impedance. This change is directly proportional to the particle’s volume, allowing precise measurement of particle size and concentration.
The Coulter principle is commonly used in particle characterization, cell counting (e.g., blood cells), pharmaceuticals, biotechnology, and industrial quality control because it provides accurate, reproducible, and number-based particle measurements.
What's a good way to measure particle size distribution?
A reliable way to measure particle size distribution is Electrical Sensing Zone (ESZ) analysis, also known as the Coulter principle. This method measures particles individually as they pass through a small aperture, delivering high-resolution, number-based particle size distributions across a wide size range.
Instruments like the Multisizer 4e Particle Analyzer apply this technique to provide accurate, reproducible particle sizing and counting for applications in pharmaceuticals, biotechnology, industrial materials, and research. The Multisizer 4e Particle Analyzer is especially effective when precise control, traceability, and true particle-by-particle measurement are required—making it a gold standard for particle characterization.
What is the difference between a Coulter counter and flow cytometry for cell counting?
A Coulter counter counts and sizes cells using the Coulter principle (Electrical Sensing Zone) by measuring changes in electrical impedance as each cell passes through a small aperture. This provides accurate, label-free total cell counts and true cell volume measurements, independent of cell color, shape, or optical properties.
Flow cytometry, by contrast, counts cells using light scatter and fluorescence as cells pass through a laser. It enables multiparametric biological analysis (e.g., surface markers, viability, phenotype) but typically requires fluorescent labeling and is more sensitive to optical and staining variability.
How to count particles regardless of their shape or color?
The most effective way to count particles regardless of shape, color, or optical properties is by using Electrical Sensing Zone (ESZ) technology, also known as the Coulter principle. This method counts particles individually by measuring changes in electrical impedance as each particle passes through a small aperture filled with a conductive liquid.
Because the signal is based on particle volume, not light scattering or imaging, ESZ analysis delivers accurate, label-free particle counting that is independent of particle shape, transparency, refractive index, or color. This makes it ideal for heterogeneous samples in biotechnology, pharmaceuticals, industrial materials, and quality control.
Instruments such as the Multisizer 4e Particle Analyzer apply this technology to provide precise, reproducible particle counts and size distributions across a wide size range.
