Gradient Forming

Gradient Forming

When we first introduced the Gradient Master in 1985, there were many approaches to gradient forming such as self-forming gradients, freezing and thawing homogeneous solutions, diffusion of step gradients, the 2-chamber device, and the syringe pump. Virtually all of these techniques were slow and unreliable, so we set out to speed up the process and make it more reproducible. The Gradient Master is the result. Starting with 6 empty tubes, you can form 6 identical gradients in as little as 10 min, producing gradients that are more reproducible than any other gradient forming technique, made right when you need to use them.


The Gradient Master™ generates linear gradients using our patented process called tilted tube rotation. The process involves layering the two end point solutions (i.e. 5% and 30% sucrose) directly in the centrifuge tube, capping it and placing it in a magnetic tube holder (MagnaBase™) that adheres to the rotary steel plate on the instrument. The Gradient Master takes over and tilts the tube to the proper angle, rotates it for a designated time and returns it to its original vertical position, ready to use.  

The introduction of the model 108 is the latest step in the evolution of this remarkable instrument. It has several new features that distinguish it from previous models. First, its memory contains all the run parameters for all the many different gradients we have developed for our customers. To see the list, select the rotor (ie SW41) you are using and then scroll through a list of the gradients organized by solute and %. To simplify things further, the “LAST” key on the keyboard recalls the last gradient run, so 2 keystrokes are all that are needed to duplicate a run. 

The Gradient Master is internet programmable, so you can download new software as upgrades become available. The gradient catalog is also upgradable so users can benefit from our ever-expanding set of run parameters. Solutes used so far include sucrose, glycerol, tartarate, Optiprep®, Nycodenz®, Ficoll®, Percoll®, Metrizamide, Renografin®, NaCl, CsCl, NaAc, KCl. The Gradient Master has never met a solute it couldn’t handle. 

If you are serious about your gradient work, there is no alternative for the Gradient Master. In nearly 2,000 labs, it has become the world’s gradient former of choice because of its simplicity, incredible speed and durability.

Western Blotting: you will find a strong similarity between the tilting Gradient Master and the tilting Navigator Western blotting device on this website. The Gradient Master’s steel plate is only 4” in diameter, so its capacity for the magnetic blotting bottles is less than the 6” or 10” plates of the Navigator. However, it is an intelligent roller blot device that can perform all the blocking, blotting and reaction steps with unerring accuracy and reproducibility. Using our patented MagnaBase™ bottles which come in a variety of sizes to fit every blot without overlap, you can reduce your reagent use by 90% while obtaining superb blots.