Permeation of gamma -globulin solution through three microfiltration membra
nes (Planova 35N (mean pore size (r) = 0.035 mum). Nucleopore(r = 0.1 mum)
and Fluoropore(r = 0.1 mum)) was investigated. A drastic increase in flux w
as found with a decrease in DNA in the feed solution, which was normally co
ntained in the protein solution as a contamination in the order of ppb. A D
NA-gamma -globulin complex having a particle size of 135-225 nm was detecte
d by dynamic light scattering measurements in the gamma -globulin solution,
The DNA-gamma -globulin complex was destroyed by the addition of 0.4 mol/l
NaCl in the gamma -globulin solution. The flux of the gamma -globulin solu
tion through Planova 35N membranes drastically increased with the increase
in NaCl concentration in the gamma -globulin solution up to 0.1 mol/l. This
is explained bq: a decrease in the DNA-gamma -globulin complex in the pres
ence of NaCl in the gamma -globulin solution. Only a slight increase in the
flux of the gamma -globulin solution through Nucleopore membranes was foun
d, on the other hand, a decrease in flux through the Fluoropore membranes w
as observed when the NaCl concentration in the feed solution of gamma -glob
ulin increased. These results suggest that the effect of flux on the concen
tration of NaCl depends on the pore sizes and structure of the membranes an
d membrane materials, (C) 2001 Elsevier Science B.V. Ail rights reserved.