Pierce™ 蛋白浓缩管 PES，3K 或 5K MWCO，0.5–100 mL

You may remove excess solvent and smaller moieties by centrifugation through a microconcentrator. This will concentrate your protein sample.

(1) Choose microconcentrator tube (available from a variety of commercial suppliers) with a protein cutoff smaller than the molecular weight of the protein in the sample. Check our Pierce Protein Concentrators PES.

(2) Add 1 µL of 20% w/v SDS to a dry microconcentrator tube (if sample does not already contain SDS).

(3) Slowly add sample (a few microliters at a time) to membrane until membrane is completely wet. Centrifuge to near (but not complete) dryness.

(4) If intention is to desalt sample or buffer exchange: Add ~50 µL water to microconcentrator and spin until nearly dry. Repeat buffer exchange. Sample will remain on membrane. Check our Zeba desalting proteins.

(5) Using a new collection tube, invert membrane and spin at low speed (1000 x g) to elute protein from membrane. Add 2X SDS-Sample Buffer containing 10 mM DTT to membrane: vortex, invert and spin. Final volume should be ~20 µL.

Find additional tips, troubleshooting help, and resources within our Protein Dialysis, Desalting, and Concentration Support Center.

We do not recommend autoclaving the PES protein concentrators. High temperatures will significantly increase the membrane molecular weight cutoff (MWCO). To sterilize, we recommend using a 70% ethanol solution.

Find additional tips, troubleshooting help, and resources within our Protein Assays and Analysis Support Center.

Yes, the PES membrane is compatible with desalting and buffer exchange. Protocols for concentrating, desalting, and buffer exchange only are provided in the product manuals.

The protein concentrator columns have an upper compartment that holds the sample, and a lower compartment. The two compartments are separated by a polyethersulfone (PES) semipermeable membrane. Centrifugation is applied to force solvent through the membrane, leaving a more concentrated sample in the upper chamber. The protein concentrator cassettes also contain a PES membrane and a unique channel design that ensures high optimal flux with no optimization effort. Unlike other systems, the fluid is passed parallel to the filter, rather than being pushed through a membrane perpendicularly, which can clog the filter. For maximum protein recovery in both columns and cassettes, samples should have a molecular weight two-fold greater than the molecular weight cutoff (MWCO) of the concentrator membrane.

Find additional tips, troubleshooting help, and resources within our Protein Assays and Analysis Support Center.

Pierce polyethersulfone (PES) protein concentrators are offered in six distinct MWCOs of 3K, 5k, 10K, 30K, 50K, and 100K, and the cassettes are offered in five membrane MWCOs of 3K, 10K, 30K, 50K, and 100K. The columns can process four different sample volumes ranges of 100-500 µL, 2-6 mL, 5-20 mL, and 20-100 mL, while the cassettes can process 0.5-6 L. Please see our selection chart and video found here (https://www.thermofisher.com/us/en/home/life-science/protein-biology/protein-purification-isolation/protein-dialysis-desalting-concentration/protein-concentrators.html).

Find additional tips, troubleshooting help, and resources within our Protein Assays and Analysis Support Center.