Amicon Ultra-0.5 mL Centrifugal Filters for Protein Purification and Concentration by Merck

"Very easy to use. However, some process optimization is needed and one needs to optimize centrifugation conditions to get consistent results."

"The filters work great. Although you have to make sure about the amount of nucleic acid you are adding, it gets clogged and doesn't concentrate the nucleic acid efficiently if the sample is beyond the limits."

"These devices can save days of re-making DNA fragments when the concentration of a recovered fragment is initially too low to use in a subsequent reaction. Neat units that fit into a standard microfuge and can shrink down 4-500ul of DNA solution (or protein or other solutions) reliably into 20-25ul volume with very little loss of DNA (smaller pieces like primers do have a reduced yield). Half an hour with one of these spin columns gives around a 15-25-fold concentration of the fragment, can produce optimal fragment concentration, and allow you to skip onto the next step of the process. Simple but extremely useful."

"These centrifugal devices are originally meant to be used for concentrating and/or desalting macromolecules [and they work very well, yielding high, consistent recoveries]. I, however, have been using them for several "off-label" passing applications and found them invaluable! Some examples: separating polymers from extended-release pharmaceutical formulations of small-molecule type drugs prior to instrumental analysis [a great alternative to SPE], measuring in vitro-release of encapsulated drugs in liposomal formulations [a faster and more representative alternative to SPE] , separating shorter length degradation products generated during stability studies of macromolecules. They are available in a wide range of volumes and nominal MW cut-offs. "

"Great results that are repeatable. Good service from Merck."

"Amicon Centrifugal Filter devices from Millipore are very efficient and reliable"

"This is a very reliable product from Amicon. It is very helpful in dealing with complex samples and is very easy to use. It has a reasonable pricing and fast purification."

"This product worked well in efficiently purifying my protein. I highly recommend it."

"Amicon Ultra concentrator filter is really fast and amazing. As they have, even for smaller volumes, reduced the loss of protein in the sample just by sticking it on to its wall. Also they are designed in such a way that it’s very easy to use. It looks like an Eppendorf tube! I will recommend this for others for using it."