Hi Prasun, Apparently, when you just mixed the peptide solution with the reservoir solution, crystals formed. After equilibration, the crystals were gone.
1) what I would try: just mix peptide and reservoir solution, but do not equilibrate, e.g. do not use a reservoir solution. This is called batch crystallization. Alternatively: Just after mixing, the pH will be somewhere between 5 and 6.5. After equilibration, it will be 6.5. Try reservoir solutions of different pH's, e.g. 6.0 and 5.5, but you might want to screen in finer steps. 2) I don't think you can use dissolved crystals for seeding. 3) The crystals you observed may also have been salt. Best, Herman -----Ursprüngliche Nachricht----- Von: CCP4 bulletin board <CCP4BB@JISCMAIL.AC.UK> Im Auftrag von Prasun Kumar Gesendet: Donnerstag, 26. November 2020 12:58 An: CCP4BB@JISCMAIL.AC.UK Betreff: [ccp4bb] Crystal dissolved while checking under microscope Hi Group: I have a peptide that got crystallized within 20-25 minutes after putting down the tray. The condition has 1.8M Ammonium Salt, 0.01 Cobalt (ii) Chloride hexahydrate and MES (0.1M) pH 6.5. I dissolved my peptide in 25 mM Sodium Accetate (pH=5). PI of my peptide is 10.2 When I checked for the first time, to my surprise, I saw crystals in the above mentioned condition. After an hour upon checking the same drops, I was unable to find the crystals and I think they are dissolved. My questions are following: 1) Can we stop the crystals getting dissolved? I have put another tray at 4 degree C, hoping that the crystals (if they appear) will be more stable. 2) Can I use the drop (in which I got crystals) for seeding? Thank You Prasun ######################################################################## To unsubscribe from the CCP4BB list, click the following link: https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.jiscmail.ac.uk%2Fcgi-bin%2FWA-JISC.exe%3FSUBED1%3DCCP4BB%26A%3D1&data=04%7C01%7CHerman.Schreuder%40SANOFI.COM%7C6a816813e98e4527d79a08d892028fa8%7Caca3c8d6aa714e1aa10e03572fc58c0b%7C0%7C1%7C637419887392170521%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=LiDMw4c%2BCI8WUXVdTjxdp4mUFxCdT0fwmULcPpK5rbo%3D&reserved=0 This message was issued to members of https://eur01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.jiscmail.ac.uk%2FCCP4BB&data=04%7C01%7CHerman.Schreuder%40SANOFI.COM%7C6a816813e98e4527d79a08d892028fa8%7Caca3c8d6aa714e1aa10e03572fc58c0b%7C0%7C1%7C637419887392180518%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=S6sCzFjNxd4bCKEYqlDpF04lSybN9DNDWpFgqyuzDbM%3D&reserved=0, a mailing list hosted by https://eur01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.jiscmail.ac.uk%2F&data=04%7C01%7CHerman.Schreuder%40SANOFI.COM%7C6a816813e98e4527d79a08d892028fa8%7Caca3c8d6aa714e1aa10e03572fc58c0b%7C0%7C1%7C637419887392180518%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=vB7uSbNFqEno7Ic%2Be7qCIRdvyqX5D8wFYHxzLGVDj30%3D&reserved=0, terms & conditions are available at https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.jiscmail.ac.uk%2Fpolicyandsecurity%2F&data=04%7C01%7CHerman.Schreuder%40SANOFI.COM%7C6a816813e98e4527d79a08d892028fa8%7Caca3c8d6aa714e1aa10e03572fc58c0b%7C0%7C1%7C637419887392180518%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=nRi7BwCb4ydblvulUT8QIElDJqWKvYOGhfa4wqoUrT0%3D&reserved=0 ######################################################################## To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 This message was issued to members of www.jiscmail.ac.uk/CCP4BB, a mailing list hosted by www.jiscmail.ac.uk, terms & conditions are available at https://www.jiscmail.ac.uk/policyandsecurity/
