Hi sorin The problem in your elution profile is that you cannot define a global threshold as the baseline is heavily bent (relative to the peak heights) and starting to fractionate at 6' is not the problem, telling the script to stop once you reach baseline at 13' is. I would try what you proposed: Given that your peak elution time points are reproducible, I'd actually work with the "watch" function and turn it on while watching OD for the given time windows. fractionate the first block when OD exceeded a certain threshold and then turn the watch function off after, say 13'. Turn it back on at 20' and fractionate into another well. Use the time as base and keep the Äkta pumping at constant speed. Curious if someone knows a better strategy! Best, matthias
________________________________ From: CCP4 bulletin board <CCP4BB@JISCMAIL.AC.UK> on behalf of Sorin Draga <sor.dr...@gmail.com> Sent: Monday, June 3, 2019 8:29:40 AM To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] AKTA FPLC fractionation peak by peak Dear all, We have an old akta system, running Unicorn 4.0, recently donated to our lab. While attempting to fractionate a protein mixture, I was unable to convince Unicorn to fractionate within given limits (say, for ex peak A between RT a and b and peak B between retention times c and d). All that I could manage to do is fractionate at a fixed time interval. For clarity, I have attached a picture below (orange square would be what we actually want to fractionate) Any help would be appreciated, as we are pressed for time ( I am certain that we are missing something simple) Thank you! [image.png] ________________________________ To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=CCP4BB&A=1 ######################################################################## To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=CCP4BB&A=1
