Quantification of proteins with a new sensitive method--zone immunoelectrophoresis assay.

Quantitative determination of proteins has been made by electrophoresis thereof in tubular canals filled with agarose gel containing antibodies. The procedure is simple and practicable. Sample volumes of a few microliter up to some hundred microliter may be added for each test. The amount of protein in a sample was found to be linearly related to the distance from the point of application (i.e. gel surface) to the front of the immunoprecipitation zone. The zone immunoelectrophoresis method shows over rocket immunoelectrophoresis the following advantages: less consumption of antibodies; much lower detection limit (0.05 microgram of protein per ml); larger concentration range with a linear calibration curve. A high correlation (0.98) between the first- and last-mentioned method was obtained for alpha 1-antitrypsin. Precision data are given for albumin and alpha-fetoprotein and typically a relative standard deviation of a few percent was obtained.