This experiment is from the official website of Parasitology, School of Medicine, Shandong University.
Operation method
Morphological observation experiments of amebas in lysed tissues
Principle
The lysogenic intraorganizational amoeba is a pathogenic amoeba. It has two periods in its life history: trophozoite and encapsulation. The tetranuclear capsule is the infectious stage, which enters through the mouth, lives in the lumen of the large intestine, reproduces by bifurcation, and is able to form a capsule, which is discharged from the body with human feces. Its basic life process is encapsulation → trophozoites → encapsulation; but under certain conditions, trophozoites can invade the wall of the large intestine, or invade the liver, lungs and other tissues through the bloodstream, causing lesions.1.Trophozoites solubilizing tissues within the trophozoite size of the amebae ranging from 10 to 60 mm, when it is separated from the tissues of symptomatic patients, it often contains ingested erythrocytes, and sometimes leukocytes and bacteria can also be seen. The trophozoites move with the aid of a single oriented pseudopod, have a hyaline ectoplasm and a granular endoplasm, and a spherical vesicular nucleus, 4-7 mm in diameter, with a thin nuclear membrane bordered by a single layer of uniformly distributed, uniformly sized perinuclear chromatin granules. But the trophozoites in the medium often have more than 2 nuclei, nucleolus is small, the size of 0.5mm, often in the center, surrounded by slender colorless filamentous structure.2. Encapsulation of trophozoites in the intestinal lumen to form an encapsulation of the process is called into the capsule (encystation). Trophozoites cannot form a capsule in organs outside the lumen or in the outside world. In the intestinal lumen trophoblasts gradually shrink, stop moving into a nearly spherical precyst (precyst), and later become a nuclear capsule and two splitting proliferation. Inside the cytoplasm, there is a special nutrient storage structure, i.e. chromatoid body, which is in the form of a short rod, which is meaningful for the identification of worm strains. There are glycogen vacuoles in the immature encapsulation. The mature encapsulation had four nuclei, round, 10-16 mm in diameter, with a smooth encapsulation wall about 125-150 nm thick. The nuclei were vesicular, similar to those of trophozoites but slightly smaller.
Materials and Instruments
Amoeba encapsulated iron hematoxylin stained specimens Amoeba trophozoites Move 1. Dissolved tissue specimens of amoebic encapsulated iron hematoxylin stain. For more product details, please visit Aladdin Scientific website.
In low magnification to find the capsule, should be in order to find in the lighter staining place, after finding to the center of the field of view to change the oil mirror observation.
The capsule is spherical, the periphery is often transparent and colorless, and 1-4 nuclei can be seen in the capsule. The nucleus was round, with a thin and black stained nuclear membrane, the inner edge of the membrane could be seen in a relatively uniform distribution of chromatophores, and the center of the nucleus had a point-like nucleolus. In the mature capsule (4 nuclei), the black-stained rod-shaped chromatoid chromatids and vacuolated glycogen vesicles (dissolved during the staining process) were not seen.
2. Live amebic trophozoites in artificial culture
A small drop of culture was aspirated from an artificial culture and examined on a slide. Amebic trophozoites are transparent and mobile under low magnification. Attention should be paid to the formation of pseudopods and the mode of movement, which is often slowed down by low room temperature or prolonged storage, and should be recognized with patience. The cytoplasm of artificially cultured trophoblasts does not contain erythrocytes. Such smears should not be observed with an oil mirror; nor should the microscope be tilted, otherwise the culture fluid will flow onto the mirror stage and contaminate the mirror and table.