In higher animals, there exists a phagocytic cell line with defense function, which is composed of white blood cells such as monocytes and granulocytes, and is an important part of the immune system in the organism. Among the leukocytes, granulocytes and monocytes are known as phagocytes because of their strong phagocytic activity.
Principle
The basic principle of the cell phagocytic activity observation experiment is that monocytes gradually evolve into macrophages after entering tissues from the bloodstream. Macrophages mainly rely on phagocytosis to deal with foreign matter; when the body is invaded by pathogens such as bacteria or other foreign matter, macrophages first move towards the foreign matter under the action of chemokines, and then stretch out the pseudopods to wrap the foreign matter, swallow the foreign matter into the cytoplasm to form phagocytosis vesicles, and then the lysosomes and phagocytosis vesicles fusion and digestion of foreign matter.
Operation method
Observation experiment on phagocytic activity of cells
Principle
The basic principle of the cell phagocytic activity observation experiment is that monocytes gradually evolve into macrophages after entering tissues from the bloodstream. Macrophages mainly rely on phagocytosis to deal with foreign matter; when the body is invaded by pathogens such as bacteria or other foreign matter, macrophages first move towards the foreign matter under the action of chemokines, and then stretch out the pseudopods to wrap the foreign matter, swallow the foreign matter into the cytoplasm to form phagocytosis vesicles, and then the lysosomes and phagocytosis vesicles fusion and digestion of foreign matter.
Materials and Instruments
Equipment: Move The basic procedure for observing phagocytic activity can be divided into the following steps: Caveat 1 Cervical subluxation method of execution of mice: the mouse is placed on the experimental table, the right hand grasps the mouse tail and pulls it backward, and the thumb and forefinger of the left hand presses down on the head; at this time, the thumbs and forefingers of both hands simultaneously give a yank outward between the cranial bone and spine to separate the cranial brain from the spinal cord, which results in the severance of the spinal cord from the medulla oblongata, and the mouse will die immediately. See Figure 4-3.2 The dorsal lymphatic sacs on either side of the caudal rod bone of the toad. See Figure 4-4. For more product details, please visit Aladdin Scientific website.
Slides, coverslips, dissecting scissors, forceps, 2 ml syringes, needles, light microscope, mice, toads.
Reagents:
① 6% starch broth (containing 0.3% Taipan blue); ② 1% chicken erythrocyte suspension.
② 1% chicken erythrocyte suspension
(1 ml of chicken blood (heparin anticoagulation) was added to 99 ml of chicken saline); ③ Mouse saline.
③ Mouse saline
④ Chicken saline
⑤ Toad saline
⑥ Ink
(I) Observation of phagocytic activity of peritoneal macrophages in mice.
A Two days before the experiment, mice were injected with 1 ml of 6% starch broth (for labeling) every day to induce the production of more macrophages in the peritoneal cavity (this operation was completed by the instructor prior to the experiment).
B During the experiment, one mouse in each group was taken from each group and injected with 0.5 to 1 ml of 1% chicken erythrocyte suspension (the needle was inserted from the lower abdomen at an angle of 45° into the peritoneal cavity). In the experiment, one mouse from each group was treated as described above and injected intraperitoneally with 0.5-1 ml of 1% chicken erythrocyte suspension (the needle was inserted from the lateral side of the lower abdomen of the mouse and stabbed into the abdominal cavity at an angle of 45°), and then gently kneaded the abdomen of the mouse in order to disperse the cell suspension evenly.
C After 30 min, 0.5 ml of mouse saline was injected into the intraperitoneal cavity, and the abdominal cavity was gently kneaded in order to dilute the fluid in the abdominal cavity of the mouse.
D The mice were killed by cervical vertebral dislocation after 3 min.
E The abdominal fluid was extracted with a syringe (cutting open the abdomen), pushing the internal organs to one side, and then the abdominal fluid was removed by the syringe. , push the viscera to one side, and aspirate the peritoneal fluid with a pipette or a syringe without a needle), drop the slice, and then cover the cover slice.
F Observe under the microscope.
(ii) Observation of phagocytosis of toad leukocytes
A Use a syringe to aspirate 0.5-1 ml of toad saline-diluted ink into the dorsal lymphatic sacs on both sides of the caudal pole bone of the toad, and place the toad in a room temperature environment.
B After about 2-3 h, use a syringe to aspirate the lymphatic fluid inside the dorsal lymphatic sacs, drop it onto a slide, and then cover with a coverslip for observation.