Simple and rapid chromatographic separation of IgM using microcolumns and stained sera

By adding two different stains to samples of serum it was possible to monitor visually the chromatographic separation of the IgM antibody-containing fraction from other serum components and to collect this fraction manually. The use of microcolumns filled with a medium of very low resistance of flow reduced drastically the time for the separation. A simple apparatus is described which allows to run up to 10 columns in periods of 3 min. Using this technique, IgM antibody-containing fractions from 20 sera can be obtained in 2 h. The efficiency of the method was demonstrated using sera from 55 patients with hepatitis A infection.