Eclipse™AF4 Asymmetric-Flow Field-Flow Fractionation System

The Eclipse™ AF4 solves many difficult fractionation, sizing and separation tasks for nanoparticles, macromolecules and colloids. Combined with a Wyatt DAWN® or miniDAWN MALS detector and Optilab® T-rEX refractive index detector, the Eclipse AF4 offers a uniquely versatile solution providing characterization of absolute molar mass and size and also conformation and conjugation.

The key advantage of asymmetric flow field-flow fractionation (AF4) over conventional SEC column chromatography is the capability to separate both colloidal and soluble components over a wide size range, from 1 nm to 1000 nm.


  • AF4 uses an open separation channel with no stationary phase and minimal surface area, and therefore generates almost no shear that can degrade sensitive samples.
  • Since very little surface area is involved, adverse interactions between the sample and the surface are minimized relative to sizing columns.
  • Its resolution is almost the same as analytical ultracentifugation; however it surpasses even this benchmark-sizing tool when one considers its flexibility, speed, and ease of use.
  • The Eclipse AF4 integrates seamlessly with various market-leading HPLC packages, such as Agilent, Thermo Scientific and Shimadzu, using high-quality pumps, degassers, autosamplers and UV detectors while replacing just the column with an AF4 channel.
  • The chassis can be ordered in three versions: for aqueous solvents (biocompatible), for organic solvents, and in a metal-free version.

For even more versatility consider the Eclipse DualTec, which supports automatic switching between AF4 and SEC as well as the hollow-fiber field-flow fractionation channel for nL-scale separations.

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