The difference is that the vacuole of epidermal cells may be purple, so it is often used in plasma wall separation and repair experiments (purple and colorless contrast); The inner epidermal cells are colorless, so we can dye them with corresponding dyes to observe various organelles, or the distribution of DNA, RNA or fat.
Temporary photo of epidermal cells of onion scale leaves
Extended data
Step of making temporary slices of epidermal cells in onion scale leaves
Wipe the glass slide and cover glass, gently hold the edge of the glass slide with one hand and thumb, and clamp the glass slide between two layers of gauze with the other hand, and gently wipe it with the index finger and thumb with even force.
2. Drop a drop of water in the center of the slide with a dropper, and the appropriate amount is the best. Water droplets are too small, which are easy to produce bubbles or dry up, which affects observation. The water droplets are too large, which easily overflow the glass slide and pollute the microscope.
3. Tear off the film on the surface of onion bulb with tweezers, preferably 0.5 cm× 0.5 cm. As in the previous step, emphasize the right amount, put the torn film into the water drop in the center of the slide, and carefully flatten it with tweezers. The bigger the torn film, the less likely it is to flatten.
4. Cover the cover glass to prevent bubbles from appearing under the cover glass.
5. Place the prepared glass slide on the microscope stage, so that the experimental materials under the cover glass are located in the center of the light hole, and focus on observation. Pay attention to this step: a. Observe with a low-power lens. B. strictly observe the operating procedures of the microscope. ⑥ Staining: Take the glass slide off the microscope stage and put it on the table for dyeing. Here, I want to tell the students that you can't dye directly on the microscope stage, otherwise it will pollute the microscope. After dyeing, the liquid around the film must be wiped off and then observed with a microscope.
References:
Baidu encyclopedia-onion