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    Gradient Fractionator


Continuous Small-Volume

MultiChannel Collector

Gradient Fractionator

BR-188 Density Gradient Fractionation System




* Gradient Fractionation System (1 page, 149k)

* Gradient Fractionation System - Data Capture Software (4 pages, 442k)


All you need to fractionate and detect gradients.

The system produces a continuous absorbance profile as the gradient is displaced from the bottom up by a dense chase solution and collected in precisely measured fractions.

This fractionation-only system does not load the gradients into centrifuge tubes.

Standard Features

  • Complete system includes tube piercing system; syringe pump; UA-6 Detector with 254 and 280nm filters, R1 Fraction Collector, Density Gradient Flow Cell, cables and tubing
  • Hands-off fraction separation
  • Seals and punctures the bottom of most common centrifuge tubes
  • Zone broadening and mixing are minimized with upward bulk flow
  • Built in Chart Recorder with Paper and Pens
  • Complete Accessory package included 
  • One-year parts and labor warranty


  • Protein interactions
  • Separation of organelles
  • Separation of mRNA, DNA
  • Cell synchronization
  • Protein isolation
  • Nucleic acid isolation

Options and Accessories

  • Fluorinert FC-40 for chasing CsCl gradients
  • Racks for various collection vessels; 96-well plate, eppendorf tube, test tubes (various sizes)
  • Detector flow cells for density gradient, chromatography and LPC
  • Programmable Software for RS-232 Recording from the UA-6 Detector



Density Gradient Fractionating System

BR-186 Gradient Fractionator with Syringe Pump

Used together, the Gradient Fractionator and Brandel's Syringe Pump provide bulk displacement fractionation at an economical price.



Gradient Fractionator, with Top Holder or Flow Cell, and Syringe Pump

BR-184 Density Gradient Fractionator

The Brandel density Gradient fractionator for 5-40 ml liquid displacement (formerly Isco) produces a continuous absorbance profile as the gradient is collected in precisely measured fractions. Zones that are undetectable by other methods are resolved, and their exact locations plotted.

Fractionation is performed by introducing a dense sucrose or other chase solution into the bottom of a centrifuged tube, thereby raising the gradient intact by bulk flow. Chase solution is injected either by piercing the bottom of the tube with a short needle, or through a needle from the top.



Gradient Fractionator, without Top Holder or Flow Cell


Gradient Fractionator, with Top Holder or Flow Cell

Options & Components

Universal Top Holder

Fractionating Needle

Gradient Flow Cell

Puncturing Needle

Accessory Package for Top Holder

Gasket & Collar Set

Accessory Package for Flow Cell

Fluorinert Solution