Currently I am using Amicon 10KDa centrifugal filters to concentrate the media from 400mL to 3mL. I noticed that this concentration method seem to consume lots of filters (these are expensive) and also I am being cautioned that centrifugal filters trap significant number of EVs, leaving only a part of EVs in the retentate. I was wondering If Tangential Flow Filtration could overcome the defects that I face with Ultrafiltration ?
Hello Manideep Chowdary Pachva;
I read you question, and am surprised by the concentration that you achieved in your process, from 400 mL to 3 mL. Can you confirm that this is correct?, since it is a very large concentration factor according with my experience with UF. I don´t know if the processing conditions that you use to get this concentration factors could have produced EV breakdown due to excessive stress conditions.
If you will concentrate so large volumes by UF (>400 mL), I do recommend that you use a UF system that operates at a larger processing scale. However you have to consider that all the UF processes, even the tangential flow ones, will produce some shear on your biomolecules that may cause some damage to them when processing.
If you will be dealing with this kind of separations on a regular basis, I suggest that you consider a larger scale cross-flow (tangential flow) ultrafiltration system such as Pellicon 2 Mini cassette from Merck- Millipore:
http://www.merckmillipore.com/MX/es/product/Pellicon-Mini-Cassette-Holder,MM_NF-C614#
With such filtration system you can start with 0.1m^2 cassettes (up to 0.3 m^2) for protein separation from about 200 mL up to 1 or 2 L. Probably some may say that the equipment implies a very high initial investment, but it is really worth it in the long run, as the membranes are totally reusable and have a long-term working period. Millipore sells a wide range of UF cassettes (from 5 kDa to 300 kDa). Besides this, you can use the system in a concentration or purification (dialysis) mode.
Other researchers recommend the use of a Amicon Stirred cells, that as I understand are dead-end filtration systems. According to the MERCK site this cells can go from 3 mL to 400 mL. The problem that I see with these systems as compared with the tangential flow ones that I described above, is that as they are dead-end flow, eventually the membranes get blocked and you need to change the membrane. Additionally, perpendicular flow should cause more shear to the biological molecules than tangential filtration.
I invite you to follow the following RG discussion on a similar question to yours, in which Amicon filtration systems are also suggested.
https://www.researchgate.net/post/Dialysis_bags_for_purification_of_protein
Hope this is helpful for your research.
- Badges
- Science topic
- Similar topics
- Control Systems Engineering
- Filtering