What should I do if the laboratory that does oral epithelial cells finds that there is a cell flow p

Use absorbent paper to absorb some water and iodine.

The reason for sucking saline with absorbent paper is that there is too much saline.

1. Reasons and analysis of the inconspicuous experimental effect.

The reason why the effect of the temporary loading experiment of making and observing human oral epithelial cells is not obvious During the experiment, the students could not remove the cells well. The book requires rinsing the mouth with water before the experiment to remove food debris from the mouth. Use the thick end of a sterilized toothpick to gently scrape the side wall of the mouth a few times.

When students scrape the wall of the mouth with a toothpick, it is usually not the epithelial cells of the mouth that are scraped off, but food debris, and it is easy to scratch the lining of the mouth. The method of collecting materials is not easy to master; The prepared iodine solution takes too long to stain well. The iodine solution is left for too long, and the iodine will not be dyed after volatilization; The microscope light is adjusted too strongly, which affects the observation effect.

Since the students have just practiced using the microscope, they are not proficient enough in dimming, and they are used to adjusting the light aperture to the maximum, and the light is too strong to affect the observation effect of epithelial cell structure.

Analysis: In fact, we only need to take the epithelial cells and make them into a panel for observation. According to the phenomenon that oral epithelial cells tend to fall off, it has been proved that it is possible to find exfoliated oral epithelial cells in saliva, and the author confirmed this idea through repeated experiments, and it is much more convenient to take cells from saliva than to scrape them off the oral cavity wall without scratching the oral cavity wall. In addition, in the experiment, gentian violet liquid was re-prepared instead of iodine solution for experiments, so as to reduce the difficulty of the experiment and achieve obvious experimental results.

2 The specific steps of the improved experiment.

2 1 Wipe the slides and coverslips clean with clean gauze.

2 2 Use a dropper to drop a drop of saline on the slide** (to prevent rupture of this oral epithelial cell).

2 3 Use the thick end of a sterilized toothpick to remove some saliva on the tongue (there are shedding epithelial cells in the saliva).

2 4 Place the saliva attached to the toothpick in the saline of the slide and apply it a few times.

2 5 Pick up the coverslip with forceps so that one end of the slide is first in contact with the saline on the slide, and then slowly cover the droplet (to prevent bubbles from appearing on the mounting).

2 6 Drop a drop of freshly prepared gentian violet solution at the junction of the coverslip and the glass slide (compared with iodine solution, the nucleus of gentian violet solution staining is more obvious than iodine solution staining), drain it from the opposite side with absorbent paper, and let the gentian violet solution spread to the entire specimen for staining. When observing, first point the microscope at the light, then adjust the aperture to a smaller position, dim the light, and put on the prepared film to adjust until it is clear.

Scrape the wall of the mouth with a cotton swab and apply it to a slide.

Just scrape back and forth a few times, there must be epithelial cells, turn the cotton swab more when applying, don't paint too loosely, otherwise it won't look good.

The basic structure of animal and plant cells includes: cell membrane, cytoplasm, and nucleus, in addition, plant cells also have cell wall nucleus, vacuoles, chloroplasts and other structures Therefore, when using a microscope to observe the temporary mounting of human oral epithelial cells, the structure that cannot be observed is chloroplasts

Therefore, a

That's not true.

A certain concentration of saline is added during the experiment to prevent the cells from absorbing too much water and bursting, and not to cause the cells to lose water and shrink. That is, to create a solution equivalent to the concentration of human tissue fluid.

When we drink water, the time for water to stay in our mouth is generally relatively short, even if the time is a little longer, the cell penetration and water absorption rate is limited, and it will not break immediately, so it does not lose a whole burst of cellulite epithelial cells.

However, the metabolism will definitely lose the cells that have been aged, but this will not have any effect on our health.

If you take a sip of water in your mouth for 4 or 5 hours, your mouth will bleed or crack due to cell breakage.

a. The basic knotted cleverness destruction of animal cells is: cell membrane, cytoplasm, and nucleus, a is correct;

b. The cell wall is the structure of the plant cell, and B. is wrong;

c. Mitochondria cannot be observed with an ordinary light microscope, and c is wrong;

d. Chloroplasts are the structure of plant cells, d is wrong;

Therefore, a

Observation of human oral epithelial cells.

1. Teaching Objectives: To further proficiently make temporary mounts and use a microscope to observe cells, explain the basic structure of human oral epithelial cells, and distinguish the main differences between the structure of animal and plant cells. Improve your skills in production and observation of temporary installations.

Design experiments, reform experiments, and make good use of their own innovation potential, so as to understand the continuous development of ideas and methods of scientific exploration, and continue to form the psychological quality of "bold and careful".

2. Teaching Focus: Explain the basic structure of human oral epithelial cells, compare the similarities and differences of animal and plant cells, and improve experimental ability and observation ability.

3. Teaching difficulties: 1. Scraping in the process of making temporary filming. 2. Observation of cell structure.

2. What is different from what is dripping in it and when making plants? (The drops are saline). Because there is no cell wall outside the animal cell, in order to make the animal cell active, it must be given an environment suitable for its location, and the normal saline is suitable for the environment in which the cell lives.

It is to maintain the normal morphology of the cells. The composition of normal saline is gram salt gram water. 3. Note that oral epithelial cells are taken from the cheeks of the mouth.

4. Because oral epithelial cells are difficult to find, it is necessary to show the students the oral epithelial cell smears that have been made, so that they can find the cells accurately.

Teaching Reflection: Because of the plant cell experiment in the previous lesson, this experiment is relatively easy for students to operate, but some students feel that it is disgusting to take cells from the mouth, so they should be taught the spirit of science. For the epithelial cells in the mouth, it is not as easy as a plant when compressing, so the teacher can first do a demonstration on the podium, so that students can understand what form these epithelial cells are in and then observe them themselves, so that it is easy for students to find the cells, and there is no need for the teacher to guide them one by one.

Many students did not find the cells when they did the experiment, although some books wrote that they could stain the coverslip before the experiment in the experiment, but for this experiment, the success rate of the coverslip first and then staining was higher.

First of all, the material, be sure to use a toothpick to gently dial the upper jaw, a little bit is enough, and then when adding iodine solution, all the materials should be invaded, and the microscopic observation is first low times and then high times.

Under the low-magnification objective, the field of view is large and bright, and the cells are thick and numerous with small ridges; And under the high-magnification objective, Sakurakushi, the field of view seen is small and dark, and the cells are large and few Therefore, option B is in line with the title Obimori.

Therefore, b