For the purpose of making a comparative study of protein compositions in Ascaris suum by sexes and body parts, extracts were prepared from whole bodies, body walls, genital organs, digestive organs and body fluid, of both sexes. And electrophoretic analysis was conducted using polyacrylamide slab gel in the presence of sodium dodecyl sulfate.

The results were as follows:

1. In this study, protein bands of each part were separated in the largest number and most clearly under 8%~12% (10%) gradient gel condition. The number of bands by body parts was 43 in body walls, 51 in genital organs, 47 in digestive organs, and 34 in body fluid.

2. When examined in terms of sex, the number of bands of whole body was 38 in females and 35 in males.

3. The electrophoretic patterns of body wall protein were in most cases similar with those seen in digestive organs. And the band with a molecular weight of 72,900 was unique to the body wall, and the 122,000 MW band was unique to the female body wall.

4. In genital organ extracts, large molecular weight proteins (more than 80,000) were more frequently met. The molecular weights showed some differences between the two sexes. Of the bands, those having molecular weights of 119,700, 100,500, 88,500 and 86,100 were unique to the female genital organs. On the other hand, the male genital organs showed unique bands having molecular weights of 87,100, 82,800, and 15,500. An unique band common to the genital organs of both sexes was one having 49,300 MW.

5. In the digestive organs evenly distributed protein bands of molecular weights of l0,000~120,000 were observed. The band having 59,800 MW was unique to the digestive organs.

6. The number of bands obtained from body fluid was comparatively small, and the number of bands having less than 30,000 MW was 7, accounting for 55% of the total protein amounts. The bands having 47,600 MW and 31,400 MW were unique to body fluid.