Hi Allegedly the very small amicon pressure concentrators [which are no longer manufactured ] can be driven to very small volumes [I have heard off people pipetting a bead of sample off the disk which is quite waxy] also because you are stirring there are no local concentration problems
regards Gary Dr Gary S Thompson NMR Facility Manager CCPN CoI & Working Group Member Wellcome Trust Biomolecular NMR Facility School of Natural Sciences University of Kent, Canterbury, Kent, England, CT2 7NZ ☎:01227 82 7117 ✉️: [email protected] orchid: orcid.org/0000-0001-9399-7636 On 19 Jan 2026, at 14:24, Matthew Snee <[email protected]> wrote: You don't often get email from [email protected]<mailto:[email protected]>. Learn why this is important<https://aka.ms/LearnAboutSenderIdentification> The sartorius ones can be spun upside-down, avoiding losses from the filter and from pipetting: <image.png> I have managed to use these to work with volumes in the 10s of ul for very poorly expressing proteins, the main drawback being any aggregates from local hyper-concentration can end up in your sample. Best wishes Matthew, ________________________________ From: CCP4 bulletin board <[email protected]<mailto:[email protected]>> on behalf of Andrea Smith <[email protected]<mailto:[email protected]>> Sent: 19 January 2026 14:20 To: [email protected]<mailto:[email protected]> <[email protected]<mailto:[email protected]>> Subject: Re: [ccp4bb] Concentrating very small amounts of protein solution Hi, I haven't used it myself, but just got a promotional email about these: https://swissci.com/product/cerocon-0-5ml-ultrafiltration-device/ [swissci.com]<https://urldefense.com/v3/__https://swissci.com/product/cerocon-0-5ml-ultrafiltration-device/__;!!PDiH4ENfjr2_Jw!BA0DmC-RbhSMuQsE7SiZgFSvbcozGgg0iOkzS_pv9v9fg9SohLs_TwwYhslDMAzwhVhqieBjqHBcFgnH0KPUSWdKZvFG4G6nPd2os52ymaCK4w$> They claim it goes down to 10uL? Best, Andrea Pondělí, Leden 19, 2026 15:15 CET, "Mark J. van Raaij" <[email protected]<mailto:[email protected]>> napsal: Dear All, the smallest centrifugal protein concentrators I know take sample volumes of 0.5 ml, like these: https://www.sigmaaldrich.com/ES/es/product/mm/ufc5010 [sigmaaldrich.com]<https://urldefense.com/v3/__https://www.sigmaaldrich.com/ES/es/product/mm/ufc5010__;!!PDiH4ENfjr2_Jw!BA0DmC-RbhSMuQsE7SiZgFSvbcozGgg0iOkzS_pv9v9fg9SohLs_TwwYhslDMAzwhVhqieBjqHBcFgnH0KPUSWdKZvFG4G6nPd2os52hAP-alg$> (but other brands are also available). In theory you should be able to get to less than 40. In practice it is difficult. A problem is that, with a total protein amount of below 0.5 mg, a significant amount of it will stick to the plastic of the tubes and the filter, so it just becomes impossible to get very small volumes. I was wondering if there are other solutions available? Or efforts to miniaturise this? (apart from lyophilisation, which is not suitable for many proteins). Best wishes, Mark Mark van Raaij Dpto de Estructura de Macromoleculas, lab B5B Centro Nacional de Biotecnologia - CSIC calle Darwin 3 E-28049 Madrid, Spain tel. +34 91 585 4616 (internal 432092) ________________________________ To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 [jiscmail.ac.uk]<https://urldefense.com/v3/__https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1__;!!PDiH4ENfjr2_Jw!BA0DmC-RbhSMuQsE7SiZgFSvbcozGgg0iOkzS_pv9v9fg9SohLs_TwwYhslDMAzwhVhqieBjqHBcFgnH0KPUSWdKZvFG4G6nPd2os51NMMpKcQ$> ________________________________ To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 [jiscmail.ac.uk]<https://urldefense.com/v3/__https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1__;!!PDiH4ENfjr2_Jw!BA0DmC-RbhSMuQsE7SiZgFSvbcozGgg0iOkzS_pv9v9fg9SohLs_TwwYhslDMAzwhVhqieBjqHBcFgnH0KPUSWdKZvFG4G6nPd2os51NMMpKcQ$> ________________________________ To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 ######################################################################## 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/
