Fundamental Studies on Paper Electrophoresis of Human Serum Protein

III. Paper-Buffer System and Electrophoretic Patterns: Some Technical Devices

Abstract

1. For the precision of densitometry, each zone of serum fractions should be geometrically so figured as to be perpendicular to the direction of electromigration on its cathodic and anodic edges and to spread bilaterally just to the both edges of a paper strip. The electrophoretic patterns suiting this request will be got when the serum is applied as a rectangularly diffused zone at the starting line. The repeated streaking method proposed by Grassmann and Hannig, and the droplets depositing method are proved to be preferable in applying the serum on paper so far as the thorough attention to avoid the disfiguring effect of the first and last droplet running out from micropipett is paid. The author, in addition, devised a special micropipett which is fitted to push out a minute amout of serum by the pressure differences of fingers and to “handwrite” a uniform streak of serum on wet paper.
2. On the paper, the migration velocities of serum fractions enhance as the water content of paper (g/cm²) increase. The increases of the tension lessen the water content of paper, subsequently leading to the slow migration velocities.
3. The distortion and disfigure of a electrophoretic pattern on a paper strip are mainly due to the differences in tension.
4. When several isolated paper strips are mounted in the same electrophoresis apparatus, the migration distance of each serum fraction on them are not generally equal, owing to the minute differences of tension among these paper strips.
5. A sheet paper with slits as shown in Fig. 6 is newly designed for paper electrophoretic use.
6. A new apparatus was devised for the facilitation of mounting a paper with slits and making the tensions of paper strips as equal as possible.
7. As each fraction on paper strips on a paper with slits has almost the same migration distance, one of these strips can be used as a guide strip for checking the eletrophoretic separation as well as for cutting off the fractions from the strips for preparative experiments. The electrophoresis using a paper with slits is especially suitable for the preparation of serum fractions. This method is named the improved preparative electrophoresis by paper srips (Yamaguchi).