Molecular Weight Cut Off

Molecular Weight Cut Off or MWCO refers to the lowest molecular weight solute (in Daltons) in which 90% of the solute is retained by the membrane^[1], or the molecular weight of the molecule (e.g. globular protein) that is 90% retained by the membrane.^[2]

This definition is not however standardized, and MWCOs can also be defined as the molecular weight at which 80% of the analytes (or solutes) are prohibited from membrane diffusion.

Commercially available microdialysis probes typically have molecular weight cutoffs that range from 1,000 to 100,000.

References

1. ^ http://www.coleparmer.com/techinfo/techinfo.asp?htmlfile=SelectFiltLab.htm
2. ^ http://www.novasep.com/misc/glossary.asp?defId=139&lookfor=&search=M