Determination of the molecular weight of IgM by thin-layer chromatography combined with immunodiffusion in normal and pathological conditions.

An immunodiffusion method combined with thin-layer chromathography was elaborated for the assessment of the molecular weight of IgM. Sera from 100 normal individuals as well as from 162 patients with different types of paraproteinaemia, 100 patients with uveitis and 55 venous umbilical cord sera were analysed. Presence of 75 IgM, besides the usual 19S IgM was detected in 21% of the normal sera, in 27% of the paraproteinaemic sera, in 30% of the uveitic sera and in 5.4% of venous umbilical cord sera. IgM level in the sera was determined by radial immunodiffusion. The authors didn't find correlation between the presence of 7S IgM and different levels of IgM.