Hi Ivan, In simple words: superdex is a few generations newer than sephadex. Main difference: superdex is a physically and chemically, tougher medium.
Among all GE healthcare beads (or the ones I know of), superdex offers the best resolution and mechanical strength (thus higher flow rate, very important for FPLC). GE healthcare’s competitors now also offer something similar to the superdex and prepacked superdex columns, so it’s worth doing a little research before the purchase. Compared to the superdex, sephadex is lower in resolution, and much lower in mechanical strength. The latter makes it not really a FPLC grade gelfiltration medium, but rather a gravity flow medium. It seems that sephadex nowadays are mainly used in desalting (spinning) columns, probably because in such situations the components to be separated have huge differences in size and the short spin columns do not complain about being compressed to 3/4 of its original length. Between superdex and sepharose there are also superose, which is lower in resolution than superdex, but may allow you to separate something larger than 600 kDalton, and Sephacryl, which I can not comment due to lack of experience with this product. I think GE healthcare sells most of these beads in both bulk form (sold in little bottles) and prepacked column form, except for the top-resolution superdex beads (10 um beads or finer), which are sold only as prepacked columns (the 10 mm diameter columns and the 3.2 mm diameter columns). Packing a high-quality FPLC grade gel-filtration column does require some skill and equipment, so I recommend you to buy the prepacked columns. I like the 10 mm diameter ones because they are quite versatile. 16 mm and 26 mm columns allow you to load more sample each time, but they use larger beads hence are slightly lower in resolution, and for small quantity of sample, the dilution is excessive. For the major characteristics of the GE (Pharmarcia) beads, please refer to the GE healthcare gelfiltration handbook linked below. The chart on page 16 (Fig 1.7. Gel filtration media fractionation range guide.) is very straight forward: https://www.google.ca/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CB0QFjAA&url=https%3A%2F%2Fwww.uni-ulm.de%2Fuploads%2Fmedia%2FGel_Filtration_02.pdf&ei=TdFWVYyROYj4yQTzg4GAAQ&usg=AFQjCNGNSSu1x9gWV8p7sXm7KoVdV_OJZQ&sig2=llZUhtkDytXo8QLNJqF_hw&bvm=bv.93564037,d.b2w&cad=rja Sigma also sells some of these media (not limited to GE products), and they also have a clear, short chart for their characteristics: https://www.sigmaaldrich.com/content/dam/sigma-aldrich/life-science/proteomics-and-protein/proteomics/chromatography_gel_filtration.pdf Zhijie From: xaravich ivan Sent: Friday, May 15, 2015 11:51 PM To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] Superdex vs Sephadex Hi fabulous cc4bbs, I had recently asked you about using HPLC or FPLC for protein purification.Now I have another question relating to that. I am trying to buy a new SEC column for the FPLC for protein purification but am getting some resistance from some experienced people in the lab who have now moved from promoting HPLC to sephadex beads instead of superdex column. Could you please suggest what is the major difference between sephadex columns and superdex columns in your personal experience? Are there any sephadex columns or just beads? I have always used superdex GE prepacked columns which have been fabulous for Gel filtration. Please advise and as always thanks in advance. ivan
