Dear Gary, Even if we can't stop loss due to protein sticking to the membrane, this small volume concentrator from Sartorius with one sided membrane works for 2-3 fold concentration.
https://shop.sartorius.com/in/p/vivaspin-polyethersulfone-centrifugal-concentrators/VS0161 Note: While taking out concentrated protein, last 20 ul if used to wash the membrane with pipette before collecting works well. Regards Samar Ballabha Mohapatra Postdoctoral Research Scholar Marmorstein Lab : 309 Dept. of Biochemistry and Biophysics Perelman School of Medicine University of Pennsylvania Philadelphia - 19104 On Mon, Jan 19, 2026 at 8:22 PM Gary Thompson < [email protected]> wrote: > 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]. 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]> on behalf of Andrea > Smith <[email protected]> > *Sent:* 19 January 2026 14:20 > *To:* [email protected] <[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$> > They claim it goes down to 10uL? > > > Best, > Andrea > > > > > > Pondělí, Leden 19, 2026 15:15 CET, "Mark J. van Raaij" < > [email protected]> napsal: > > > > Dear All, > > the smallest centrifugal protein concentrators I know take sample volumes > of 0.5 ml, like these: https://www.sigmaaldrich.com/ES/es/product/mm/ufc5010 > [sigmaaldrich.com] > <https://urldefense.com/v3/__https://www.sigmaaldrich.com/ES/es/product/mm/ufc5010__;!!PDiH4ENfjr2_Jw!BA0DmC-RbhSMuQsE7SiZgFSvbcozGgg0iOkzS_pv9v9fg9SohLs_TwwYhslDMAzwhVhqieBjqHBcFgnH0KPUSWdKZvFG4G6nPd2os52hAP-alg$> > (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 > ######################################################################## 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/
