Since you are using iron oxide nanoparticles, why not capture them on magnetic racks and simply rinse off anything that is not attached with several washes ?

it depends on the size of your sample you want to clean. Usually twice molecular weight of cut-off will be saved in your bag.

Dialysis is rather straight forward. You would need to first get a suitable dialysis tube. If you plan to retain your nanoparticles you would need to know first the size of your particles.

But considering that you are making iron oxide nanoparticles, I would assume there is a degree of magnetism on it. So why don't you just wash the nanoparticles and resuspend it in the buffer you want by magnetic separation. Don't quite get your experiment still.

I think the 14kDa MWCO will be good for the removal of small molecules, in your case excess ammonia and iron cations but not dextran T40. You may use dialysis bag of at least 40kDa, this way you may let dextran T40 out as well as all the smaller particles.

25K MWCO should help.

there are good (but expensive !!) dialyzing cassettes that are suitable to recover the full sample. these are slyde-a-lyzer, that you can find easily on the web.

These cassettes allow you to inject and recover your sample with a syringe. There exists different cut-off and volumes.

They are also useful if you want to add magnets to create a magnetic field in the cassette, which won't help you in your application…

Yes, the larger the MWCO the better off you will be to speed up the process. How much volume are you talking about it? That is important to determine what diameter dialysis membrane you need. If you use conventional dialysis tubing, you should remove glycerol and potential inhibitors by boiling it. There should be a procedure for it in one of the volumes of 3-volume Molecular Cloning.

The size of pores on dialysis bag greatly different and you should use appropriate cutoff for your molecules according to the size of your particles and you should change the buffer several times during dialysis to have more dialyzed product.

By using 14K cutoff dialysis membranes might not solve your problem. You may have to couple it with another method; may be a small ion exchange chromatographical method or so.

Sigma-Aldrich make D9652 dialysis tubing cellulose membrane with typical molecular weight cut-off = 14,000 is suitable.

Thanks you all. Comments are very helpful

the cutoff of dialysis tube must be less than the molecular weight of dialysed particles (e.g. if you need to purify any particles with 25,000 D you must use dialysis tube with cutoff less than 25,000 D) to pervent the exit of your particles in dialysed buffer

14-25 KDa cut -off bags should be useful. It is a relatively simple procedure and you can refer to this paper, to see how dialysis was used for preparation of nanoparticles.

Article Low temperature synthesis of hydroxyapatite nano-rods by a m...

Since you are using iron oxide nanoparticles, why not capture them on magnetic racks and simply rinse off anything that is not attached with several washes ?

Since your sample has dextran macromolecules, 14,000 cut off might not help. I think dextran is much bigger molecule. Other molecules will be removed even if you use 8,000 cut off. You can remove dextran by gel filtration if it can done with your sample.

Please tel me hw to perform a drug release studies of poor water soluble drug using dialysis bag method.

if any paper with detail experimental details send me please.

I would support Kian's Idea, it is much faster and more efficient to make an adsorption and/or centrifugation or maybe a direct ultracentrifugation; your washing would be much more efficent and a lot faster

Dear Rozita

You can use one of the following methods:

1- Dialysis (please use the dialysis bag with lower cut off to remove all other particles)

2- Gel filtration chromatography (G-100 and then G-50 can be useful)

Dear Raj, Please find the attached paper to carry out release experiments using dialysis bag. You can prepare a drug suspension using 0.3% w/v sodium CMC and take drug suspension in a dialysis bag and dip it in release medium.

Thank you Sumeet Sood

One thing to consider is how MW cutoffs are determined. This is often done by using particles of known MW distribution, then assigning the MW cutoff value to the minimum particle size for which at least 90% was excluded over a period of 16-24 hours. With that caveat, if you want a more complete exclusion over 24 hours, you might consider using a MW cutoff somewhat smaller than 14 kD.

In present case a benzolylated dialysis bag with MWCO of around 12KD-14KD would be suitable. This bag would efficiently remove the carrying out dialysis in double distilled water. The dialysis can be continued for 18-20 hours.