Pierce™ Dextran Desalting Columns, 5K MWCO, 5 mL, 5 Columns - FAQs

Besides precipitation with ammonium sulfate, what are some ways I can concentrate my protein sample?

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 Assays and Analysis Support Center.