Hey everyone!
I have a few peptide sequences synthesized using SPPS and all of them are in the M.wt range of 6 to 8kDa. I've done MALDI MS and found out that I do have the desired peptide peak but plenty of other peaks as well spread out over 4 to 8kDa range (capped chains, truncated products and whatnot). It is quite difficult to do HPLC purification and collect 20+ fragments and do MALDI again. Is it possible to use some molecular weight cut off columns (say MWCO 5 or 6 kDA) and remove the peaks below 5kDa range so that we have relatively less peaks to isolate in HPLC??
Hello. Yes, you can do that. MilliporeSigma sells a popular line of molecular weight cutoff filters called AmiconR Spin Filters. I don't think there is a 5 kDa option but you can check also PierceTM Protein Concentrators from Thermo, which should have a 5 kDa cutoff. There are other manufacturers as well, just search for spin filters with molecular weight cutoff. Be mindful that those molecular weight cutoffs are nominal.
Additional time and cost effective options suitable for small scale are:
1) Hollow fiber TFF (check Sartorius and Cytiva, for example)
2) Mini-dialysis (check Slide-A-Lyzer line from Thermo, for example)
3) Run gel electrophoresis and extract your desired bands
(I just assumed you are working on small scale, by the way)
Petroslav Chipinski That's very helpful! Thank you for the suggestions! I'll explore into them and go for one of those!
- Badges
- Science topic
- Similar topics
- Agricultural Science
- Agronomy
- Crop Science