What molecular weight cutoff dialysis membrane to use for virus concentration - (Oct/02/2006 )
Does anyone know how uwould work out the molecular mass of a virus particle.........here is my problem - I want to concentrate my virus using dialysis, or ultrafiltration but all the membranes for dialysis and the ultracentrifugation devices are sold based on their molecular weight cut off values. I use rota virus which has a diameter of 70 - 80 nm, but how do i work out which molecular mass cut off point to use. . . .surely it cannot be to add up the weights of the individual components in this case because that would give a large number, but because everything is folded up tightly into the virus particle i feel a smaller cut of point should be used. I dont want to cause the pores to be clogged/blocked by choosing too small a cut off point, nor do i want to lose the virus by using too large a cut off point. Has anyone had to use a similar method for concentrating virus?
basically, it comes down to summing up all of the components...
but depending on what you want to seperate from your virus I'd recommend MWCO's from 10 to 120 kDa (more likely at the 120kDa end), which will let small molecules pass through (water, salt, monomers etc.), but will hold bigger proteins and complete virus particles back....
Mike
Considering some large proteins, such as ferritin is ~ 500,000 with a diameter of 8 nm and your virus is considerably larger than that. MWCO upto 500,000 seems to be safe to use. However, dialysis tubing with a MWCO of 12,000-14,000 is most commonly used and the cheapest one you can get.
is it possible to concentrate virus using tubing dialysis? For changing buffer or desalting is fine., you will get the same volume after dialysis. or is there some trick to concentrate using dialysis?
basically, it comes down to summing up all of the components...
but depending on what you want to seperate from your virus I'd recommend MWCO's from 10 to 120 kDa (more likely at the 120kDa end), which will let small molecules pass through (water, salt, monomers etc.), but will hold bigger proteins and complete virus particles back....
Mike
Hej Mike,
you can easily use 100 cutoff or as before mentioned 120 cutoff membrane. I tryed concentrate with membrane units from amicon for 50 nm viruses using 100 cutoof, it works fine. but you will loose some concentration, if your viruses have tail, some of them gonna to be destroyed. Also there is some new zeba columns from pierce. But this columns just for desalting and changing buffer, not for concentrating.
is it possible to concentrate virus using tubing dialysis? For changing buffer or desalting is fine., you will get the same volume after dialysis. or is there some trick to concentrate using dialysis?
The answer is yes. If you add virus solution to the dialysis tubing and add PEG powder (20,000 kDa) on the outside. You can have large volume reduced in 30 min. No spin is needed. You have to be careful not to over dry the sample, because the liquid can be absorbed very fast.
is it possible to concentrate virus using tubing dialysis? For changing buffer or desalting is fine., you will get the same volume after dialysis. or is there some trick to concentrate using dialysis?
The answer is yes. If you add virus solution to the dialysis tubing and add PEG powder (20,000 kDa) on the outside. You can have large volume reduced in 30 min. No spin is needed. You have to be careful not to over dry the sample, because the liquid can be absorbed very fast.
Hi genehunter-1
do you have a reference for this or a proper protocol?
Stardust
No. I dont have one. You may test it with buffer solution to get a sense how fast it works.
I believe you can also use high MW polyacrylic acid powder as well.
I believe you can also use high MW polyacrylic acid powder as well.
Thank you, i might try it...
Stardust