Since we are operating our Äkta Avant in a multiuser environment, we need to separate the methods and results of the different users.
After we solved all the teething troubles with our Äkta Avant, we finally dare to let customers use it. Most of them find it difficult to understand the behaviour of the fraction collector...
The most common protein purification technique that we use is gel filtration (also called size exclusion chromatography). In gel filtration, proteins are separated by their size (or more correctly by their "Stokes radius", which is largely determined by their size and shape). For gel filtration of large protein amounts, we bought GE Healthcare's HiLoad 26/60 Superdex 200 prep grade about 9 years ago. The performance of the column is outstanding. Being used to 30-cm-columns, we were amazed how well the column separates between e.g. dimeric and monomeric forms of our pet protein. However, the column lost dramatically its performance recently...