Dear Researcher,
Protein purification is hard graft but obtaining a homogeneous preparation of your favourite protein at the end of a long procedure can be highly rewarding. Unfortunately, sometimes the final preparation is too dilute for it to be stored safely without causing significant sample losses over time, or it could simply be too dilute for the desired downstream application, be it crystallization trials, popping it in an NMR tube, or for a complicated enzyme assay.
There are different ways to concentrate proteins but one of the most popular is ultrafiltration owing to the speed and ease of the procedure. 
Many users are not aware though that a significant proportion of the centrifugal concentrators on the market have filters made of polyethersulfone (PES). PES is a sticky surface for proteins and can cause significant losses of precious samples.
At Cambio we offer Orbital Biosciences Apollo concentrators.The Apollos are centrifugal concentrators that come in 7 mL and 20 mL versions and the filters are made from regenerated cellulose making them much less prone to non-specific binding of most proteins and in particular proteins that exhibit some degree of instability under the conditions in which they are purified.
If you would like to test a free sample of a pair of Apollo concentrators of a particular molecular weight cut-off then contact us on and we will ship them out to you next day delivery. All feedback is welcomed!
Did you know Apollo 150 kDa concentrators are also useful tools to concentrate viral supernatants too?
Cambio Ltd
 1 The Irwin Centre, Scotland Road, Dry Drayton, Cambridge, CB23 8AR
Tel: 01954 210200
Fax: 01954 210300