7 - THE TECHNIQUE OF IMMUNELECTROPHORESIS IN AGAR GEL

Abstract

This chapter discusses the technique of immunelectrophoresis in agar gel. Differences in the electrochemical properties of the relevant body fluids have been extensively used to promote separation; but no substantial progress, from an analytical point of view, was possible until a further property of proteins was exploited. Immun-electrophoresis enables up to 22 proteins and related substances (lipoproteids, glucoproteids, mucoproteids, acetalphosphatide) to be distinguished qualitatively. In this respect, it differs basically from paper electrophoresis, of which the greatest advantage is that it offers a quantitative evaluation by means of a simple technique. With immun-electrophoresis (Im.EI) it has also become possible to recognize atypical serum proteins and thus obtain a new insight into the mechanism of acquired immunity, and congenital defective dysproteinaemia. The protein mixture to be separated (serum, cerebrospinal fluid, lymph, ascites, protein fractions, etc.) is first subjected to electrophoresis in agar gel. After the fractions have been adequately separated, a suitable antiserum is poured into a depression in the agar gel which is along the migration path of the proteins. The antiserum gradually diffuses laterally to meet the protein fractions. At those place where homologous antigens and antibodies meet, slightly curved precipitation lines form.