A micromodification of the electroimmunoassay

A micromodification of the Laurell electroimmunoassay is presented. The immunoelectrophoresis is run vertically in 50-μl capillary tubes keeping the immunoglobulin-containing agarose gel. The method has high accuracy, and for proteins the detection limit is 0.1 ng. The quantitative limit is 1.0 ng with a mean variation coefficient of 6.8%. Besides the sensitivity the method also has practical advantages as it is easy to handle and requires no expensive equipment. In addition, the consumption of immunoglobulins is extremely low, which renders the method rather economical. The antibody-containing gel tubes can be stored for long periods. This makes it possible to run several samples against the same antibody-gel batch, which increases the speed and simplicity of the method.