NMWCO

Polyamide/hydrophilic Hollow fiber — 10 50kDa (NMWCO) Forschstung Institut Berghof, (Germany) o/w emulsions [29]... 

Membrane manufacturers prefer to use a parameter called the nominal molecular weight cut-off (NMWCO) or simply the molecular weight cut-off (MWCO) to specify the sieving properties of their membranes. For a given membrane this is defined as the molecular weight of a solute that has an apparent sieving coefficient of 0.1. Polymers, such as dextran or polyethylene glycol, are usually used to determine MWCO. 

The retention characteristics of ultrafiltration membranes are measured in Nominal Molecular Weight Cutoff (NMWCO). The NMWCO can be controlled during membrane formation and is typically available in 1,000 10,000 100,000 and 1,000,000 daltons. For cell harvesting, ultrafiltration membranes of 100,000 NMWCO and microporous membranes are generally employed. While the separation is based on size, the efficiency of the operation can be influenced by other factors. 

Mycoplasma are fermented for the production of veterinary vaccines and diagnostic tests. In this particular fermentation, the cultivation medium, PPL0 broth, contains serum as a.growth component and the fermentation is typically carried out ig 250 liter volumes. Successful separations are performed with 50 ft of a 100,000 NMWCO ultrafilter in the same configuration and under the same operating conditions as the E. coli example (Table III). 

Ultrafiltration was used to speed up the concentration step and as a substitute for dialysis in washing the concentrated virus. In this modified centrifugation process, the total number of centrifuges was reduced almost in half and the processing time with each centrifuge lowered from 8 hours to k hours. Final concentration of a 30 liter batch was accomplished with 30 ft of 100,000 NMWCO ultrafiltration membrane. Inlet pressure was 20 psi and the outlet pressure was 10 psi (Table V). 

A range of filters in a variety of technically advanced materials - areas from less than Isq mm to over Isq m - separation down to less than 3000 Dalton NMWCO) and less than... 

---